Pro Tip: When you use the TDR like that, run it from both ends and make sure it matches. That way you know you don't have a discontinuity near the other connector.
@@garycook5125 Open or just higher impedance that might look fine at DC. Say you have a 30' piece of coax and the TDR says 29.75', you might think it's fine. Measure from the other end and if it says 29.75' then it is fine, but if it says 0.25' you know something's wrong.
Another diagnostic, unplug the coax from the antenna and insert a dummy load instead. Back to the shack, normal SWR / RL measurement. You should get a good SWR from 1 to 1000MHz with a good 50ohm load on the coax because you don't have a frequency dependant load (antenna) there anymore. All good? It's not the coax, it's the antenna.
Always be safe when you go on the roof. If it has too much "slope", better play it safe and get a professional. Oh, I would not recommend the Secret Service.
If the roof is too sloped, look on Craigslist for a teenager with experience at Blackrock - I've heard good things about their ability to deal with sloped roof designs.
When wrapping your connections @18:06, always start the wrap below the connection, and work your way up. Do not start wrapping from above the connection. If wrapped from the bottom- up, the wrap overlaps itself like roof shingles do, encouraging water to flow over the wraps instead of in between them. Some people never figure out how water gets in their coax; this is normally what they did wrong.
I installed a tri-band (23cm/70cm/2m) antenna from Diamond that is mechanically identical to your antenna (from what I can see in the video), and it's worked very well for more than 20+ years. I took it down when I moved last year and inspected it. Everything was as perfect. I did a quick cleaning on it and painted it white again since I could just barely see fiberglass underneath the original paint in some areas. I reassembled it, put it back together and it's back up again. Works like a charm. I think the build quality of the Comet/Diamond antennas is top notch. Good Luck!
Josh I tried to look through the comments and not sure if I have seen this listed. I have several repeaters and also help some with the Skywarn Linked Repeater System here in Georgia. The capacitors in those antennas (all brands) are notorious for popping with lightning static hits. Many people will take off the "store bought" caps and replacing them with higher voltage caps. Also many folks will solder the brass fittings after tightening them. REAL important to also leave the weep hole at the bottom of the antenna open. Even when sealing up the coax to the antenna. You may not have the issues in CA but here in GA, with the humidity, heating and cooling... lots of moisture can happen within those radomes. Robert KD4YDC
I too am running the same CX-333 and it has been a fantastic performer on all three bands. It has held up very well for the past 2 years it has been up here it HOT Florida. Great video as always Josh!
Josh, you do such a great job with your presentation skills; clear voice, no wind noise when outside, excellent speaking voice, same tonal volume, all of which makes it so easy to follow your presentations. Great job on this video, loved it.
Fiberglass gel coat coming off, and maybe fiberglass splinters... you can rough it up with sandpaper and paint it to use it as a mast for something... You should cut the electrical tape and push it down with no tension on it when you reach the end. Stretching makes it loosen over time. If exposed to wind it can then unravel. My electrician dad hollered at me if I stretched and broke the tape!
I went to HRO Anaheim today, first time ever. I walked in and said, "Josh sent me! " :) Lol, one guy said " Josh sends everybody!" (Really nice guys in there btw. I was very impressed actually, lots of knowledge, awesome place overall) I bought the Kenwood D75 and a few accessories to go with it. Anyhow, I appreciate you Josh. Great YT channel. KM6PIR ...73 👍
Ha, you threw me for a loop. Early on I was like "oh no and you had engine trouble too?" (your front "engine" hood was open). "Ohhhh, it's electric." Silly me.
TDR = Time Domain Reflectromity. It pinpoint the change in impedence on the line. Which in your case is the open end of the coax, and in others the location of the 1st fault in the line. Every VNA can do this, including the nano VNA
I have the Comet GP-98 2/70/23 tri-bander in use here. It has the same plastic collar joining the 2 sections in the center. I put 3M self amalgamating tape over it since the UV here in Australia will turn it to dust in a couple of years. They are a good antenna with nice performance on 1.2Ghz.
The CHA-250 is a good antenna and works well across all the bands with very good SWR. It is not the best, but I have made contacts world wide with it. I do recommend that it be secured with guy wires as it is not very wind resistant. It does bend a lot with strong winds and if you have a little ice with the wind it will bend over. Don't ask how I know. Been through 2 of them. It is not a real efficient antenna (some signal loss to heat) but it does work pretty well. Good luck!
Your boy is going to use that as a lance or sword. :) When weatherproofing, you start from the bottom and work up, yes in direction of "tight" for the connector. Your overlaps can catch water starting top down. We used to wrap with 3m electrical tape (bottom up), then self amalgomating, then 3m electrical and then coated it with some scotch brown gooey product. This was for shipboard antennas in the navy. But always bottom up because of the overlaps and how water would flow over it.
I've had a Diamond X510 (model name may have changed since I bought it 15-18 years ago), 17.2 foot tall and has survived 90+ mph winds, hail that whacked my roof to the tune of 25k worth of damage, etc. Best 2m/70cm vertical ever made in my very humble opinion. Still working like a charm. Just for grins, years back, i plugged in my yeasu FT90 and talked simplex, through 50 ft of cable full quieting over 30 miles. Comet has been around for a while, but Diamond is the way to go. Yikes, just watched the assembly and construction. You do you brother, lol.
The box on your house with "lightning arrestors", is a set up that is encouraging disaster in your radio room (if not your entire house). First, the line that you said is run to your panel, needs to be run directly to its own ground rod as close as you can get it to the antenna box. Disconnect it from your electrical panel. Run a solid piece, do not splice ground wiring. Next, if you insist on running a ground wire from inside the house, it needs to run directly to the ground rod I told you to connect the first line to (disconnect it from box copper plate). Again, run a solid line to rod, do not splice two cables. Just remember, having a ground rod running outside creates potential ground voltage differential that can backfire on you. Your radios are already connected to ground via the three-way A/C outlets. Ideally, all of your equipment should be powered by 1500 or larger UPSs that not only serve as backup power, but also isolate your equipment from surges in your house A/C wiring. This in itself, negates any need to run additional ground wires to an outside ground rod. Why? The way it is now, lightning current is being given a path from your antenna cables, directly to your radio room via the arrestors and copper plate. Eliminating this path gives lightning strike current only one way to go (down to the rod). Note: I'm not your typical Amateur radio licensee.
For mission critical infrastructure in almost arctic conditions we do the same weatherproofing, first we seal the joint with self-amalgamating tape, then overwrap with 3M Super 33+ or Super 88. Every layer extends 1-2 inches past the last layer, so self-amalgamating goes an inch past the connectors up the cable, then the electrical tape an inch past that. The brand of the self-amalgamating tape isn’t that critical, though prices vary wildly, so make sure to check electrical supply houses etc. However, the brand and type of electrical tape is the key here, it has to be either of those. If you haven’t tried it before, this isn’t your normal electrical tape, it’s thicker, stickier, doesn’t dry out or crack in the sun etc.
Hi Josh, Nice installation video. Also good on weatherproofing the coax connector. Some say the CHA-250HD is only a dummy load. Doubt Comet would risk their reputation on an antenna that doesn't work as advertised. 73 WJ3U
I also use that coax shield or self sealing tape to wrap my trailer wiring harness. It gives the wires and plastic wrap an extra layer of protection from road and rodents.
Nice job Josh. I've had a CX-333 up on my garage roof for almost 10 years, still a perfect match on all 3 bands. Great quality base antenna! Good job with the weather proofing! Here in rainy Vancouver, it is a must!
Speaking of too many hobbies, I just scored a drone, and I'm working on even more licensing. You can never have too many hobbies. I just need to make time for the fun ones now. I'm on the hunt for a triband, and i need to resurrect the good old yaesu ft60. I only need a battery, but I'm thinking upgrade to one of the other, slightly newer, yaesu ht's that's waterproof and triband. Thank you, as always, for the awesome content. I've been missing streams, but I'm still a member because I love the way you help the world with your content, brada man. 🤙🏾
Great job Josh ! Love the coax weather seal you did ! great triband antenna ! Comet had great stuff ! I use a product from M & P called silicone seal and it comes in 2 sizes. You put it over the joint you want to seal and pull the string. It is cold shrink. If you seen the Pota flex 6 or 7 kit with winder the ends have the silicone seal installed on it. Another great way to waterproof joints. 73
Couple of tips on the weather- proofing; The electrical tape should be started below the connection and run up towards the top of the antenna. This will shingle the tape so water has no potential pockets to run into. We usually wrap 3 or 5 times (always an odd number to maintain shingling). At the end, on the very last wrap, never stretch the tape or tear it. Cut it with a sharp knife or scissors and that will keep the tail from eventually peeling back off.
Took one of these Tri bands apart once and the problem was a dry joint on the small capacitor on the loading coil it would swr ok on uhf but high on lower bands
You might be able to save that MFJ pulsar. If it's similar to the Comets and Diamonds - the issue might just be one of the disc capacitors in the base.. Usually they go open, short or burn out. Nice job Josh
Can't wait for your Comet CHA-250HD install. I have one because I can only install a vertical and can't run counterpoises, and its been great! particularly with the Yaesu inbuilt auto tuner.👍
Waiting for that test. I'm looking for an HF vertical to mount on a 17 foot mast above my townhouse without anything that attaches to the building per the hoa rules. Also must meet up with the architecture committee requirements. 73's KG7COA
Always great videos that you share with us. Thanks again to you Josh and the good 73s.....Too bad that in France we no longer have adequate stores for amateur radio (no stores of this type for at least 20 years) unlike the USA. Joel/F8MGW.
Those brackets aren't supposed to mount to the wall, they are meant to couple to a piece of mast pipe. If you were to get that above your roof line the SWR would be "flat as a pancake". I've had a 333 deployed for a number of years now, amongst others. 73 N8WWR
They sell Rescue tape at ace that is multiple colors. Same silicone stuff and it works really well. Always use 3M 33+ Did electrical work all my work days and 3M is assume!
One recommendation I would make… when you’re taping your connections, start at the bottom and wrap upwards. Why? Water will usually enter a connection from the top rather than the bottom. When you wrap from the bottom up, the seams are facing downward, not unlike roof shingles.
lucky you Josh having a ham shop near you,for me in the UK my nearest shop is 160 miles away,but theres a cafe just down the road that does a killer full english breakfast so the journey is doubly worth it, boy i though my shack was chaotic ,yours trumps mine by a country mile :) :)
A nice, clean antenna installation. Good job! As for the CHA-250HD for your next project, I can’t wait to see that video. It is a compromise antenna on hf , for sure. Even Comet’s own ad says so. However, it should work moderately well. I can’t say for sure but it looks to be a variation of the Rybakov antenna. Good luck and keep up the good work!
The two brackets @12:43 that come with the antenna are not designed to be bolted to the side of your house, or anything else. U-bolts use those holes, to attach it to a mast. The mast is what should be secured to your house via house brackets @9:45 that you used with your first antenna. Do not screw or bolt those U-bolt brackets to the side of your house.
Those brackets it comes with are really intended to mount to a mast with the provided U bolts. My suggestion would be to get a 5’ section of mast, with some appropriate mounts to mount the mast to the house, and then mount the antenna to the top of the mast.
Hi Josh, I've been watching for a while - Just subscribed. I work commercial LMR installs in the UK - Mostly Motorola. TDR - Time Domain Reflectrometry Send a signal down an unterminated coax, and the signal will hit the far end and bounce (high SWR). Measure the magnitude of the reflected signal and the TIME it took to return, and you will know the distance to the "fault" (could just be the end of the cable). You can only do this if you know the speed of the signal. RF speed is constant, so the only variable is the VF (Velocity Factor) of the coax (speed of Rf through that particular design of coax). You need to enter the VF into the meter so that it can work out the speed - if it doesn't know the VF, it can't know the speed so it is not going to measure the distance to fault accurately. Colinears: Pretty much all colinears are made the same. The tube is fibreglass with gel-coat finish. The tube is sealed to the fittings with epoxy resin (JB Weld). Once the antenna has had some years in the sun, the infra-red and ultra-violet attack, and this causes the gel-coat to oxidise (white residue) and the epoxy to become brittle. The good news, is that the actual antenna part is literally just a copper wire. It is effectively impervious to the weather, and it is only put into the tube to keep it upright. Fibreglass tubes: Sand with 600 wet and dry paper, rinse off with water, dry them and then hit with spraypaint of your choosing. You now have another 10 years out of them. The epoxy may be discoloured, but I'll wager it is just fine - the various manufacturers seem to have learned that cheaping out on the epoxy resin = bad reputation. Pull the wire out of the tubes and just clean up the ends with scothbrite. The tarnishing on the radials is not a problem. Even at DC, you would need something like a micro-ohmeter to measure the resistance. Flush the connector end of the antenna out with carb-cleaner and then send a blast of deoxit through and you will be golden. Reassemble exactly as you did - Self amalg-tape starting from the bottom (overlaps like tiles for water run-off) and then cover the self amalgamating tape with electricians tape - Self amalg is not UV stable wheras electricians tape is. Try to leave less coiled up cable flapping in the wind - it will weaken the joints and lead to issues like you had. Get some proper cable cleats for LMR to secure it. Hope this helps!
Wow, I have been assuming that my antenna is fine but after watching this I am going to lower it and check ALL of the connections and weather proofing. The weather in Tenn can be extreme and change very quickly.
Any vertical antenna I install, I always have a habit of making a 4-5 turn loop of the coax and securing it to the mast below the radials for an additional choke to prevent any current coming back down to the shack.
If you run the self-amalgamating tape from lower to higher on the connection, there’s less chance of water ingress, because of the way that the tape overlaps on the upper layers.
The installation of the antenna was covered by others.I will cover the safety aspects of this (as an IRATA technician)The cheapest/safest/efficient way is to use a safety harness with a fall arrest lanyard.You know you'll be servicing-visiting your antenna so a permanent anchor near the antenna will be your best bet.A fall from 3 meters (10 ft) might be lethal.OSHA will thank you
I wrap my connections from the bottom up so that the rain/water runoff flows over the bottom of the tape "loops" instead of the top edge. My logic is that it keeps any loops that have loosened from allowing water intrusion. Just my $.02.
I have the CHA250 HD antenna on an Icom 7300. I’ve contacted Florida to New Zealand on 10 meters recently. Only one contact on 6 meteres ever in four month. All bands have low SWRs
That CHA-250HD is a pretty solid HF vertical antenna. I have one about 18' in the air. Ideal setup? No. But I've made plenty of contacts with it. Will be interested in your experience with it. T
i like that tape used to work for a cable co. used it a lot .. but any set screws on antennas i use anti seize on the treads or Vaseline ..being close to st.Mary's bay nova scotia .salt water .corrosion is a major factor
As far as sealing the cable with tape, that first tape may be fine, but electrical tape really isn't great for high temps such as years of being outside. Something to consider is there is a product called duct seal that many electricians use for exterior penetrations that is rated for the severe duty of being in an exterior environment.
Hey Josh, I'm actually looking forward to the CHA-250 HD Install and test. There are some antenna build videos of that model on YT but I don't think I have seen a test. I have seen Diamond BB7v which seem similar to the Comet and users were pretty happy. I always thought Comet and Diamond were owned by the same people but found out they are completely different entities. Thanks as always for the great content. 73
So you have a lightning arresting system. As a relatively new ham, I wish I could get clarity on this issue. I've watched so many videos and read so many lengthy treatises on this subject lately by supposedly very knowledgeable experts in radio and electricity who can't seem to agree: 1. whether lightning arresting is needed for antennas and radios, and 2. if so, how best to achieve that. Everyone seems to have a different, very strongly opinionated take on the subject. Since it concerns safety, it'd be nice to have definitive consensus on this issue. Anyway, sorry for diverting from the main topic; thanks for showing your new antenna installation - looks awesome!
You should use good lighting protection. If that is grounding at the antenna source or tower or lightning arrestors at a property installed ground rod as close to antennas as you can you’ll have the best results. Regardless of the best lightning protection if you take a direct hit you’ll still likely lose radios. In most cases the goal is to dump static from the antenna system.
Great video. love to see more of these. I know that HRO very well. Been there several times. I could tell you a Covid story about the service I got there. It ended up to be a good ending but only because another store employee who cared stepped in. So a couple of questions. What about shrink-wrapping your coax cover / electrical tape for more protection. Your cut away of the old antenna did show you don't need it but it was a thought. i know this was a time issue but what about Ed Fong's TBJ-1 tri band "J" pole antenna. I don't know what you paid at HRO but I believe this is about $70.00 All SWR testing went below 1.5 to 1, and only 7 feet or so tall.
I managed to make a software matrix mixer work for me with my FT-710 thanks to a fellow from your discord! It's not perfect, it requires me to reconfigure if I want to run digi and not have my mic bleed into it. But I'm sure that a hardware interface would do the same thing.
Was exactly my thought. JEALOUS!!! No radio shops left in my state as far as I’m aware (Michigan) but feel free to please fill me in if there are any I’m not aware of….
@@ROBIN_SAGE my friend from church owns a small shop called ham-sters in Dowagiac, MI and we have a radio shack in Niles, MI. They don't have everything but between the two I have been able to pick up some needed goods sometimes.
Major Jealous Moment - watching you drive to HRO. Out here, I would drive to Chattanooga to Chatt Radio (only 45 minutes). Other than that, we have HRO in Atlanta (3 hours) and GIGAPARTS in Huntsville (3 hours). Good for you! KQ4IXD
I like your box setup. It is pretty much the way a broadcast station should do it, "ground"as close to the electrical entrance as practicable and then run through the building to the radios. Thanks for sharing this video K1AUS
Off topic but I must post this comment . I just had the honor of listening to , while reading the translation of Jeff Beals , Life Eulogy . Being transmitted at eighteen words per minute , ( CW ) absolutely phenomenal ! Unto Jeff Beals , his eternal Soul , Jeff Beals family , praise be unto God , seated at the right hand of His Father , A Kingdom that has no END , Godspeed Mr. Beals , and He is said To Go .
I read from a professional radio direction finder producer, that it's better to place aluminum foil around bottom of magnet, then place thin felt piece between the aluminum foil and the car body. Supposedly, a regular 3" magnet at VHF frequencies has about 473pF. With the aluminum and felt, more like 1,700pF.
I would like to know what happened to the old antenna. The white chalky stuff was likely paint of fiberglass (depending on if it was metal or fiberglass). You said no water got in and the connections were not corroded so this is puzzling to me.
Good one Josh though would argue the direction of winding the tapes. At least the insulation tape should be wound from under the connector to the top as if there is moisture at all it would tend run over the lap down falling onto the next ayer. Theoreticaly the moisture doesn't sit on the next wrap below allowing possible ingress between the wraping layers. Yes but who am I to argue hi. Thanks man cheers from VK5 land.
Ok safety tip If you are going up on the roof make sure you have someone around Incase you do fall !!! But if you are going to be in a safety harness but all means have someone around and have a plan to be able to get you out quickly !!!! The problem with a safety harness is it cuts off the blood to your legs and causes major problems if you are hanging in one longer than 10 minutes !!!!!!! You can tie rope to parts of the harness with a loop in it big enough to be able to get your foot into so you can kind of use your legs to stand up so to say to relive the pressure and get blood flow back !!!! Also your anchor point must be sturdy There is a tremendous amount of load and shock when you stop falling also if you do fall go to the ER and get checked out !!!!!
The self amalgamating tape wrap direction doesn't really matter, but I always wrap it and the protective electrical tape from the bottom up so it acts like shingles on a roof to shed rain water. Why leave edges up for water to more easily ingress if the adhesive fails somewhere? Remember Murphy's Law. 73 mike 🍺🍻
I saw your video today about replacing your UHF/VHF ham antenna. From the looks of things, it appears that you're in the Phoenix area, with the Ham Radio Outlet nearby and the architecture of the house next door (it looks like a typical John Long tract home). If so, I'm wondering what you intend to do with the "stinger" assembly from your old antenna. I've been looking for something like that for a "home build" project I'm working on. Thanks!
Pro Tip: When you use the TDR like that, run it from both ends and make sure it matches. That way you know you don't have a discontinuity near the other connector.
Ohhh. Yes. I forgot that!
"discontinuity"?
You mean "open"?
@@garycook5125 Open or just higher impedance that might look fine at DC. Say you have a 30' piece of coax and the TDR says 29.75', you might think it's fine. Measure from the other end and if it says 29.75' then it is fine, but if it says 0.25' you know something's wrong.
Another diagnostic, unplug the coax from the antenna and insert a dummy load instead.
Back to the shack, normal SWR / RL measurement. You should get a good SWR from 1 to 1000MHz with a good 50ohm load on the coax because you don't have a frequency dependant load (antenna) there anymore.
All good? It's not the coax, it's the antenna.
Always be safe when you go on the roof. If it has too much "slope", better play it safe and get a professional. Oh, I would not recommend the Secret Service.
If the roof is too sloped, look on Craigslist for a teenager with experience at Blackrock - I've heard good things about their ability to deal with sloped roof designs.
One time I had to climb a roof that was three degrees steeper than straight up.
🤣🤣🤣
Dude. I only take advice about roofs from the secret service.
When wrapping your connections @18:06, always start the wrap below the connection, and work your way up. Do not start wrapping from above the connection. If wrapped from the bottom- up, the wrap overlaps itself like roof shingles do, encouraging water to flow over the wraps instead of in between them. Some people never figure out how water gets in their coax; this is normally what they did wrong.
I installed a tri-band (23cm/70cm/2m) antenna from Diamond that is mechanically identical to your antenna (from what I can see in the video), and it's worked very well for more than 20+ years. I took it down when I moved last year and inspected it. Everything was as perfect. I did a quick cleaning on it and painted it white again since I could just barely see fiberglass underneath the original paint in some areas. I reassembled it, put it back together and it's back up again. Works like a charm. I think the build quality of the Comet/Diamond antennas is top notch. Good Luck!
Now I understand the whole weather proofing the coax and antenna. Thanks Josh!
Yessir!
Josh I tried to look through the comments and not sure if I have seen this listed. I have several repeaters and also help some with the Skywarn Linked Repeater System here in Georgia. The capacitors in those antennas (all brands) are notorious for popping with lightning static hits. Many people will take off the "store bought" caps and replacing them with higher voltage caps. Also many folks will solder the brass fittings after tightening them. REAL important to also leave the weep hole at the bottom of the antenna open. Even when sealing up the coax to the antenna. You may not have the issues in CA but here in GA, with the humidity, heating and cooling... lots of moisture can happen within those radomes. Robert KD4YDC
I too am running the same CX-333 and it has been a fantastic performer on all three bands. It has held up very well for the past 2 years it has been up here it HOT Florida. Great video as always Josh!
Josh, you do such a great job with your presentation skills; clear voice, no wind noise when outside, excellent speaking voice, same tonal volume, all of which makes it so easy to follow your presentations. Great job on this video, loved it.
Thank you!
Fiberglass gel coat coming off, and maybe fiberglass splinters... you can rough it up with sandpaper and paint it to use it as a mast for something...
You should cut the electrical tape and push it down with no tension on it when you reach the end. Stretching makes it loosen over time. If exposed to wind it can then unravel. My electrician dad hollered at me if I stretched and broke the tape!
I cleaned a fiberglass antenna with sandpaper and recoated it with polyester resin. It worked out well.
LOL... Guitar Center "the place you go to lust after stuff that you won't buy"... almost the same can be said for HRO!
I love how all these people are giving you advice. blows my mind. shaking my head. thanks for all you do.
People can’t help it. 🤣
I went to HRO Anaheim today, first time ever. I walked in and said, "Josh sent me! " :) Lol, one guy said " Josh sends everybody!" (Really nice guys in there btw. I was very impressed actually, lots of knowledge, awesome place overall) I bought the Kenwood D75 and a few accessories to go with it. Anyhow, I appreciate you Josh. Great YT channel. KM6PIR ...73 👍
Awesome! Glad you had fun!
Ha, you threw me for a loop. Early on I was like "oh no and you had engine trouble too?" (your front "engine" hood was open). "Ohhhh, it's electric." Silly me.
I totally did the same thing
yeah, me too! :-)
You should wrap the tape like shingles on your roof, bottom to toop, such that water runs off not in.
Standard in commercial installation is up down up. Three layers
@@KI5UCO Think about shingles.
TDR = Time Domain Reflectromity. It pinpoint the change in impedence on the line. Which in your case is the open end of the coax, and in others the location of the 1st fault in the line. Every VNA can do this, including the nano VNA
I have that exact antenna. Will be going back up again soon.
Awesome, has it worked well for you?
@@HamRadioCrashCourse very much so. I also have a GP9, but like having the tri-band. Also I wrap the connections.
Better to start from the bottom then wrap up so the tape over laps like roof shingles so water flows over the seams not collecting.
I have the Comet GP-98 2/70/23 tri-bander in use here.
It has the same plastic collar joining the 2 sections in the center.
I put 3M self amalgamating tape over it since the UV here in Australia will turn it to dust in a couple of years.
They are a good antenna with nice performance on 1.2Ghz.
The CHA-250 is a good antenna and works well across all the bands with very good SWR. It is not the best, but I have made contacts world wide with it. I do recommend that it be secured with guy wires as it is not very wind resistant. It does bend a lot with strong winds and if you have a little ice with the wind it will bend over. Don't ask how I know. Been through 2 of them. It is not a real efficient antenna (some signal loss to heat) but it does work pretty well. Good luck!
Your boy is going to use that as a lance or sword. :) When weatherproofing, you start from the bottom and work up, yes in direction of "tight" for the connector. Your overlaps can catch water starting top down. We used to wrap with 3m electrical tape (bottom up), then self amalgomating, then 3m electrical and then coated it with some scotch brown gooey product. This was for shipboard antennas in the navy. But always bottom up because of the overlaps and how water would flow over it.
I have sealed many antenna’s on navy ships just like you described. I have been trying to figure out the name of the gooey stuff.
@@judd_s5643 I think it may be petrolatum tape?
@@judd_s5643 Are you thinking of Scotchkote?
I've had a Diamond X510 (model name may have changed since I bought it 15-18 years ago), 17.2 foot tall and has survived 90+ mph winds, hail that whacked my roof to the tune of 25k worth of damage, etc. Best 2m/70cm vertical ever made in my very humble opinion. Still working like a charm. Just for grins, years back, i plugged in my yeasu FT90 and talked simplex, through 50 ft of cable full quieting over 30 miles. Comet has been around for a while, but Diamond is the way to go. Yikes, just watched the assembly and construction. You do you brother, lol.
I am using a Diamond Dual Band Vertical that is 28 years old! It still works great!
I've had a CX-333 up for 3 years. Great antenna!
The box on your house with "lightning arrestors", is a set up that is encouraging disaster in your radio room (if not your entire house). First, the line that you said is run to your panel, needs to be run directly to its own ground rod as close as you can get it to the antenna box. Disconnect it from your electrical panel. Run a solid piece, do not splice ground wiring.
Next, if you insist on running a ground wire from inside the house, it needs to run directly to the ground rod I told you to connect the first line to (disconnect it from box copper plate). Again, run a solid line to rod, do not splice two cables. Just remember, having a ground rod running outside creates potential ground voltage differential that can backfire on you. Your radios are already connected to ground via the three-way A/C outlets. Ideally, all of your equipment should be powered by 1500 or larger UPSs that not only serve as backup power, but also isolate your equipment from surges in your house A/C wiring. This in itself, negates any need to run additional ground wires to an outside ground rod.
Why? The way it is now, lightning current is being given a path from your antenna cables, directly to your radio room via the arrestors and copper plate. Eliminating this path gives lightning strike current only one way to go (down to the rod).
Note: I'm not your typical Amateur radio licensee.
Sorry I misspoke. The service panel and my box all go directly to the ground installed by the service.
I just installed a CX-333 at my house. Works great so far! Very low noise and low SWR as advertised.
For mission critical infrastructure in almost arctic conditions we do the same weatherproofing, first we seal the joint with self-amalgamating tape, then overwrap with 3M Super 33+ or Super 88. Every layer extends 1-2 inches past the last layer, so self-amalgamating goes an inch past the connectors up the cable, then the electrical tape an inch past that. The brand of the self-amalgamating tape isn’t that critical, though prices vary wildly, so make sure to check electrical supply houses etc. However, the brand and type of electrical tape is the key here, it has to be either of those. If you haven’t tried it before, this isn’t your normal electrical tape, it’s thicker, stickier, doesn’t dry out or crack in the sun etc.
Hi Josh,
Nice installation video. Also good on weatherproofing the coax connector. Some say the CHA-250HD is only a dummy load. Doubt Comet would risk their reputation on an antenna that doesn't work as advertised. 73 WJ3U
Thank you!
I also use that coax shield or self sealing tape to wrap my trailer wiring harness. It gives the wires and plastic wrap an extra layer of protection from road and rodents.
Nice job Josh. I've had a CX-333 up on my garage roof for almost 10 years, still a perfect match on all 3 bands. Great quality base antenna! Good job with the weather proofing! Here in rainy Vancouver, it is a must!
Speaking of too many hobbies, I just scored a drone, and I'm working on even more licensing. You can never have too many hobbies. I just need to make time for the fun ones now.
I'm on the hunt for a triband, and i need to resurrect the good old yaesu ft60. I only need a battery, but I'm thinking upgrade to one of the other, slightly newer, yaesu ht's that's waterproof and triband.
Thank you, as always, for the awesome content. I've been missing streams, but I'm still a member because I love the way you help the world with your content, brada man. 🤙🏾
Thank you! I appreciate the support!!
Great job Josh ! Love the coax weather seal you did ! great triband antenna ! Comet had great stuff ! I use a product from M & P called silicone seal and it comes in 2 sizes. You put it over the joint you want to seal and pull the string. It is cold shrink. If you seen the Pota flex 6 or 7 kit with winder the ends have the silicone seal installed on it. Another great way to waterproof joints. 73
I now need to do the same with a dual band antenna. Thnx for the tips. :)
Couple of tips on the weather- proofing;
The electrical tape should be started below the connection and run up towards the top of the antenna. This will shingle the tape so water has no potential pockets to run into. We usually wrap 3 or 5 times (always an odd number to maintain shingling).
At the end, on the very last wrap, never stretch the tape or tear it. Cut it with a sharp knife or scissors and that will keep the tail from eventually peeling back off.
Running the same CX-333 anteanna and it works great on all three bands. Also have a box from KF7P which is fantastic! Enjoyed the video.
Took one of these Tri bands apart once and the problem was a dry joint on the small capacitor on the loading coil it would swr ok on uhf but high on lower bands
You might be able to save that MFJ pulsar. If it's similar to the Comets and Diamonds - the issue might just be one of the disc capacitors in the base.. Usually they go open, short or burn out. Nice job Josh
That seems to be the consensus. I might take a look.
Can't wait for your Comet CHA-250HD install. I have one because I can only install a vertical and can't run counterpoises, and its been great! particularly with the Yaesu inbuilt auto tuner.👍
When wrapping tape/coax seal, always start from the bottom and wrap up so the layers overlap like shingles on a house.
I've had my Maldol dual band antenna up for 15+ years. It still works well. Bob, W2OSR
Waiting for that test. I'm looking for an HF vertical to mount on a 17 foot mast above my townhouse without anything that attaches to the building per the hoa rules. Also must meet up with the architecture committee requirements. 73's KG7COA
I have maybe 20 guitars in my house at the moment, and I salute your self control!!!
Always great videos that you share with us. Thanks again to you Josh and the good 73s.....Too bad that in France we no longer have adequate stores for amateur radio (no stores of this type for at least 20 years) unlike the USA. Joel/F8MGW.
Have been using a CX-333 for a couple of years, absolutely no issues.
Those brackets aren't supposed to mount to the wall, they are meant to couple to a piece of mast pipe. If you were to get that above your roof line the SWR would be "flat as a pancake". I've had a 333 deployed for a number of years now, amongst others. 73 N8WWR
They sell Rescue tape at ace that is multiple colors. Same silicone stuff and it works really well. Always use 3M 33+ Did electrical work all my work days and 3M is assume!
One recommendation I would make… when you’re taping your connections, start at the bottom and wrap upwards. Why? Water will usually enter a connection from the top rather than the bottom. When you wrap from the bottom up, the seams are facing downward, not unlike roof shingles.
Seems like a perfect antenna for the th-d75
lucky you Josh having a ham shop near you,for me in the UK my nearest shop is 160 miles away,but theres a cafe just down the road that does a killer full english breakfast so the journey is doubly worth it, boy i though my shack was chaotic ,yours trumps mine by a country mile :) :)
Very dangerous to be as close as I am.
Ain't R and L fun?
Hope you have fun with the 250. For being "the antenna that doesn't work" I've heard plenty of great things about it.
A nice, clean antenna installation. Good job! As for the CHA-250HD for your next project, I can’t wait to see that video. It is a compromise antenna on hf , for sure. Even Comet’s own ad says so. However, it should work moderately well. I can’t say for sure but it looks to be a variation of the Rybakov antenna. Good luck and keep up the good work!
The two brackets @12:43 that come with the antenna are not designed to be bolted to the side of your house, or anything else. U-bolts use those holes, to attach it to a mast. The mast is what should be secured to your house via house brackets @9:45 that you used with your first antenna. Do not screw or bolt those U-bolt brackets to the side of your house.
Those brackets it comes with are really intended to mount to a mast with the provided U bolts. My suggestion would be to get a 5’ section of mast, with some appropriate mounts to mount the mast to the house, and then mount the antenna to the top of the mast.
I'm needing to finally expand my qth shack with vhf/uhf capabilities. Thanks for the video.
Hi Josh,
I've been watching for a while - Just subscribed.
I work commercial LMR installs in the UK - Mostly Motorola.
TDR - Time Domain Reflectrometry
Send a signal down an unterminated coax, and the signal will hit the far end and bounce (high SWR). Measure the magnitude of the reflected signal and the TIME it took to return, and you will know the distance to the "fault" (could just be the end of the cable). You can only do this if you know the speed of the signal. RF speed is constant, so the only variable is the VF (Velocity Factor) of the coax (speed of Rf through that particular design of coax). You need to enter the VF into the meter so that it can work out the speed - if it doesn't know the VF, it can't know the speed so it is not going to measure the distance to fault accurately.
Colinears:
Pretty much all colinears are made the same. The tube is fibreglass with gel-coat finish. The tube is sealed to the fittings with epoxy resin (JB Weld).
Once the antenna has had some years in the sun, the infra-red and ultra-violet attack, and this causes the gel-coat to oxidise (white residue) and the epoxy to become brittle.
The good news, is that the actual antenna part is literally just a copper wire. It is effectively impervious to the weather, and it is only put into the tube to keep it upright.
Fibreglass tubes: Sand with 600 wet and dry paper, rinse off with water, dry them and then hit with spraypaint of your choosing. You now have another 10 years out of them. The epoxy may be discoloured, but I'll wager it is just fine - the various manufacturers seem to have learned that cheaping out on the epoxy resin = bad reputation.
Pull the wire out of the tubes and just clean up the ends with scothbrite.
The tarnishing on the radials is not a problem. Even at DC, you would need something like a micro-ohmeter to measure the resistance. Flush the connector end of the antenna out with carb-cleaner and then send a blast of deoxit through and you will be golden.
Reassemble exactly as you did - Self amalg-tape starting from the bottom (overlaps like tiles for water run-off) and then cover the self amalgamating tape with electricians tape - Self amalg is not UV stable wheras electricians tape is.
Try to leave less coiled up cable flapping in the wind - it will weaken the joints and lead to issues like you had.
Get some proper cable cleats for LMR to secure it.
Hope this helps!
I’ve been looking at the 250hd so I’ll wait to see the results.
I am running the same CX-333 and it has been a fantastic performer on all three bands. Good tips in the vid.
Wow, I have been assuming that my antenna is fine but after watching this I am going to lower it and check ALL of the connections and weather proofing. The weather in Tenn can be extreme and change very quickly.
Any vertical antenna I install, I always have a habit of making a 4-5 turn loop of the coax and securing it to the mast below the radials for an additional choke to prevent any current coming back down to the shack.
If you run the self-amalgamating tape from lower to higher on the connection, there’s less chance of water ingress, because of the way that the tape overlaps on the upper layers.
The installation of the antenna was covered by others.I will cover the safety aspects of this (as an IRATA technician)The cheapest/safest/efficient way is to use a safety harness with a fall arrest lanyard.You know you'll be servicing-visiting your antenna so a permanent anchor near the antenna will be your best bet.A fall from 3 meters (10 ft) might be lethal.OSHA will thank you
I wrap my connections from the bottom up so that the rain/water runoff flows over the bottom of the tape "loops" instead of the top edge. My logic is that it keeps any loops that have loosened from allowing water intrusion. Just my $.02.
A couple layers of shrink wrap always works for me cheers sir u k
the white powder stuff is aluminum oxide,
On a fiber glass pole??
@HamRadioCrashCourse didn't know it was fiberglass because a lot of them also I see I'm made out of aluminum
Have a CX-333 on my roof and it's been a great antenna.
I have the CHA250 HD antenna on an Icom 7300. I’ve contacted Florida to New Zealand on 10 meters recently. Only one contact on 6 meteres ever in four month. All bands have low SWRs
That CHA-250HD is a pretty solid HF vertical antenna. I have one about 18' in the air. Ideal setup? No. But I've made plenty of contacts with it. Will be interested in your experience with it. T
That same guy helped me out last time I was at HRO. Very nice guy. He even offered me a donut and coffee.
And now I see you got the coffee also :)
i like that tape used to work for a cable co. used it a lot .. but any set screws on antennas i use anti seize on the treads or Vaseline ..being close to
st.Mary's bay nova scotia .salt water .corrosion is a major factor
As far as sealing the cable with tape, that first tape may be fine, but electrical tape really isn't great for high temps such as years of being outside. Something to consider is there is a product called duct seal that many electricians use for exterior penetrations that is rated for the severe duty of being in an exterior environment.
Good to see how u wrapped the coax with the seal, the electrical tape, etc; I always wonder if I'm doing it the best way possible, LOL 👍😃🇺🇸
Great video Josh ! Yes to the expensive 3M electrical tape.
Suggestion: Add a grommet to that opening in the back of the antenna box.
Hey Josh, I'm actually looking forward to the CHA-250 HD Install and test. There are some antenna build videos of that model on YT but I don't think I have seen a test. I have seen Diamond BB7v which seem similar to the Comet and users were pretty happy. I always thought Comet and Diamond were owned by the same people but found out they are completely different entities. Thanks as always for the great content. 73
Love the antenna box. I have 2 of them from him
So you have a lightning arresting system. As a relatively new ham, I wish I could get clarity on this issue. I've watched so many videos and read so many lengthy treatises on this subject lately by supposedly very knowledgeable experts in radio and electricity who can't seem to agree: 1. whether lightning arresting is needed for antennas and radios, and 2. if so, how best to achieve that. Everyone seems to have a different, very strongly opinionated take on the subject. Since it concerns safety, it'd be nice to have definitive consensus on this issue.
Anyway, sorry for diverting from the main topic; thanks for showing your new antenna installation - looks awesome!
You should use good lighting protection. If that is grounding at the antenna source or tower or lightning arrestors at a property installed ground rod as close to antennas as you can you’ll have the best results.
Regardless of the best lightning protection if you take a direct hit you’ll still likely lose radios. In most cases the goal is to dump static from the antenna system.
Great video. love to see more of these.
I know that HRO very well. Been there several times. I could tell you a Covid story about the service I got there. It ended up to be a good ending but only because another store employee who cared stepped in. So a couple of questions. What about shrink-wrapping your coax cover / electrical tape for more protection. Your cut away of the old antenna did show you don't need it but it was a thought.
i know this was a time issue but what about Ed Fong's TBJ-1 tri band "J" pole antenna. I don't know what you paid at HRO but I believe this is about $70.00 All SWR testing went below 1.5 to 1, and only 7 feet or so tall.
I would add the weather proofing to the middle point as it will provide protection to the plastic from the sun
I am curious about that no radial required HF antenna. Looking forward to that video.
I managed to make a software matrix mixer work for me with my FT-710 thanks to a fellow from your discord! It's not perfect, it requires me to reconfigure if I want to run digi and not have my mic bleed into it. But I'm sure that a hardware interface would do the same thing.
Wow, so first of all, you have a Ham Radio Outlet nearby ? Wow
Was exactly my thought. JEALOUS!!! No radio shops left in my state as far as I’m aware (Michigan) but feel free to please fill me in if there are any I’m not aware of….
I have a cousin who isn't even an operator who's been to one before me.
@@ROBIN_SAGE my friend from church owns a small shop called ham-sters in Dowagiac, MI and we have a radio shack in Niles, MI. They don't have everything but between the two I have been able to pick up some needed goods sometimes.
Major Jealous Moment - watching you drive to HRO. Out here, I would drive to Chattanooga to Chatt Radio (only 45 minutes). Other than that, we have HRO in Atlanta (3 hours) and GIGAPARTS in Huntsville (3 hours). Good for you! KQ4IXD
Same here, HRO is 3hrs, MTC is 3.5, and D&L(?) is 3.5 hrs.😢
I like your box setup. It is pretty much the way a broadcast station should do it, "ground"as close to the electrical entrance as practicable and then run through the building to the radios.
Thanks for sharing this video
K1AUS
Thanks for watching!
Im glad i dont use ladders much anymore, last time i used a ladder similar to yours i fallen off my inlaws roof in longpine comiefornia.
Very cool to see your install.
Off topic but I must post this comment . I just had the honor of listening to , while reading the translation of Jeff Beals , Life Eulogy . Being transmitted at eighteen words per minute , ( CW ) absolutely phenomenal ! Unto Jeff Beals , his eternal Soul , Jeff Beals family , praise be unto God , seated at the right hand of His Father , A Kingdom that has no END , Godspeed Mr. Beals , and He is said To Go .
Good to know the Anaheim HRO is still open.
I have a CHA-250B works great all over with a LDG RT 100 remote tuner. 👍
If you wrap the tape from the bottom to the top, the wrap will offer better resistance to water.
I read from a professional radio direction finder producer, that it's better to place aluminum foil around bottom of magnet, then place thin felt piece between the aluminum foil and the car body. Supposedly, a regular 3" magnet at VHF frequencies has about 473pF. With the aluminum and felt, more like 1,700pF.
I would like to know what happened to the old antenna. The white chalky stuff was likely paint of fiberglass (depending on if it was metal or fiberglass). You said no water got in and the connections were not corroded so this is puzzling to me.
As always, another great video Josh!!! 73!
Thanks for watching
Good one Josh though would argue the direction of winding the tapes. At least the insulation tape should be wound from under the connector to the top as if there is moisture at all it would tend run over the lap down falling onto the next ayer. Theoreticaly the moisture doesn't sit on the next wrap below allowing possible ingress between the wraping layers. Yes but who am I to argue hi. Thanks man cheers from VK5 land.
Was that a Thomas Guide I saw in the seat back pocket?!? Ultimate LA prep tool for the big one! Nice antenna, hope it's a winner.
Yes it is!
Ok safety tip
If you are going up on the roof make sure you have someone around Incase you do fall !!! But if you are going to be in a safety harness but all means have someone around and have a plan to be able to get you out quickly !!!! The problem with a safety harness is it cuts off the blood to your legs and causes major problems if you are hanging in one longer than 10 minutes !!!!!!!
You can tie rope to parts of the harness with a loop in it big enough to be able to get your foot into so you can kind of use your legs to stand up so to say to relive the pressure and get blood flow back !!!!
Also your anchor point must be sturdy There is a tremendous amount of load and shock when you stop falling also if you do fall go to the ER and get checked out !!!!!
The self amalgamating tape wrap direction doesn't really matter, but I always wrap it and the protective electrical tape from the bottom up so it acts like shingles on a roof to shed rain water. Why leave edges up for water to more easily ingress if the adhesive fails somewhere? Remember Murphy's Law. 73 mike 🍺🍻
Nice antenna works well 😊
"you can only have so many hobbies" haha
Always enjoy your how tos and reviews. Way off topic, but, how do you like your Lightning? Brother has one.
I really like it. I think the key charging at home.
@@HamRadioCrashCourse Absolutely. The tech in the vehicles is so far ahead of the public charging network buildout.
I wish I had an HRO closer than a 5 hour round trip. Oh, wait, that might be bad... 🤣
Yeah. It can be bad.
Electrical taping is an art, looks good
I saw your video today about replacing your UHF/VHF ham antenna. From the looks of things, it appears that you're in the Phoenix area, with the Ham Radio Outlet nearby and the architecture of the house next door (it looks like a typical John Long tract home). If so, I'm wondering what you intend to do with the "stinger" assembly from your old antenna. I've been looking for something like that for a "home build" project I'm working on. Thanks!