I bought several antennas, mounts, studs, springs, and cables to test with a RigExpert(55) meter. Tired of some local ‘experts’ opinions that seem more about my wallet than my radios. Have used the meter to move a coworkers mag mount and dialed in great SWR with a cheap antenna . The RigExpert confused me at first but I’m liking it now.
I drive an Outback and I use the Shark HF sticks. I had the exact same problem you are experiencing. But I don't think its the roof rack as much as it is the poor capacitive coupling of the magnet base. They way I solved the problem was to add 25 feet of coax to my mag mount. I believe this creates a counterpoise of sorts as the resonant point of the antenna drops right into the band. I've done this on vehicles both with and without roof racks with similar results.
What if by adding the spring to the base of the antenna you've actually added physical and electrical length to the antenna? You were resonating high in frequency which is indicative of an antenna which is too short for the desired resonant frequency. But when you added the spring you added both mechanical and electrical length to the antenna making the antenna longer which lowers the resonant frequency of the antenna. What is inside that spring to connect the antennas radiating element to the center conductor of the coax? My guess is bare copper wire. The couple inches of copper wire added to the electrical length of the antenna is certainly long enough to lower the resonant frequency of the antenna. Most certainly the metal within the roof rack has some influence on the antenna as it is less than 1/4 wave away from the antenna. While there is a null immediately below the vertical dipole, the metal frame of the roof rack is 90 degrees from the feed point of the antenna. I imagine that the lobe of the vertical antenna is quite wide at the feed point, perhaps wide enough to be influenced by the roof rack.
Absolutely right! My tri-mag mount (Tram) tunes everything so much better than a single mag. The extra capacitive coupling to the roof metal makes a BIG difference ... averaging SWR of 1.1 to 1.4:1 at resonance on all HF bands. Even when I moved it around the roof, there is very little difference in performance. I only use a single mag mount for VHF/UHF. I don't recommend HF on a single mag mount for optimal results 😀 73 KJ6ER
Hi there. i have on occasions experienced similar unexplained problems. There is a likelihood that your VSWR readings are being affected by common mode currents. Try installing a ferrite core choke near the base feed point of the antenna. Sometimes a choke at feed point to the transceiver will also correct this problem. Give it a try. 73 Peter G3OJV
Interesting experiment! One variable not discussed but is an elephant in the room is that the mag mount capacitively couples the ground plane. It would be interesting to note how a solid electromechanical connection via a mount drilled into the roof would affect resonance. Another thing to consider is... since there is no good electromechanical connection to the ground plane, the coax is also acting as a non resonant counterpoise, and it ALSO is capacitively coupled to the body of the car as you move the target around on the roof. This experiment DOES prove how dubious the ground plane is when capacitively coupled via a magnetic mount and when there is not solid connection of the antenna to the ground plane. You may wish to further test your conclusions with these additional considerations. Best 73's Dan. K1YPB - On the air since 1962.
When I first started messing with whip antennas on top of cars using my MFJ whip on a magnetic mount, I noticed that by moving my coax around I would get unpredictable results. I wrapped my coax around a toroid as many turns as I could fit (they certainly give you enough coax for mobile use) as close to the antenna as I could. This eliminated common mode currents and interaction with the car body. I haven't had a problem tuning my antenna since making the modification. KE8RWW, 73.
Thank you for this. Looking at what you've found, I think I'll use my Wolf River Coils Mimi antenna not only as a base but also as a way to tune my hamsticks more precisely Only for my 75 meter stick.i can use the WRC mini as a stand alone for the other bands
I use hamsticks for my POTA activations. I started with a 2014 Dodge Caravan, and a 5" mag-mount, and the hamsticks I have cover 10m through 75m. This set up was used for 3 years and 390 successful POTA activations. Last August I traded in the van and bought a 2022 Nissan Frontier. I was worried that the much smaller roof of the truck would detune the hamsticks. What I discovered is that nothing changed, the hamsticks still tune the way they did on the old vehicle, and I'm now up to 465 successful activations. I operate exclusively SSB or CW QRP. Thanks for the interesting video and lots of food for thought.
Hello chap, I had similar issues a few years back as my Volvo has roof rail too. I found that putting a choke in line made a big difference, also, adding capacitive strip to the mag-mount too solved all the issues. Allan G6HPR
Hi, Just wondered if you thought of using a piece of faraday cloth and laying it on the vehicle roof under the mag mount? It's very pliable and would not scratch paint finish. It seems to be an effective ground plane and is becoming popular with hams operating portable, replacing radials and metal screens. Good luck . VE3WNS
Good experiment Tracy! Very interesting outcome! Hamsticks seem to be notorious for difficulty in tuning on anything anywhere. Some have had success cutting the whips down a few inches. I used a 10,20, and 40m MFJ Hamstick on the top center of my extended cargo van. No rack rails and no sunroof. Right out of the package they all 3 were resonant somewhere within the band they were intended for. I put the same Hamsticks on top of my KIA Soul with no racks or sunroof and couldn’t get them to tune anywhere near their intended band. After hours of trying I gave up. I might try cutting the whips down and see if that helps. 🤔
I would have liked to see you compare the front hood to the roof of your vehicle. More metal, but perhaps less coupling with the rest of the vehicle. It was also suggested to me when I first started using hamsticks, to go to a tri-magnet mount. I can only say that I have had little or no problem tuning my collection of hamsticks and Hustlers. I next ran a section of insulated wire, electrically connected to the magmount to a bolt in the hinge of one of my rear doors. Having moved from an suv to a truck and camper, I next bought a 3' extension to lift my hamstick up by 3 feet. The rationale was that I was getting some reaction between the antenna and the camper . All good so far, and no problem tuning. Thx for the great vid. Brent
Hi Brent, thank you for your comment. The hood of the Outback is not magnetic or I would have shown that configuration. I like your idea of using an extension and a connection to the car battery.
hi Tracy. nice experiment. have you tried to join a light telescopic antenna with a crocodile clip and put it at the tip of the stick, shorten and extend it to see the difference in results? most people i know use those antennas just for listening on the move, but when they want to do QSOs they park and add radials. I saw michael's comment about mag mount capacitance coupling and went to watch his video. I have a couple of ham sticks but never used them for mobile. only as a rigid dipole.
Tracy you need to put a feed line choke between the rig expert and the antenna . Secondly the adapter has raised the base of the antenna off the magnet mount and the magnet needs to be a minimum of 5" diameter for best results .
I used to use Hamsticks on an F-150. I cut a 20m and 40m radial and ran them to the back of the truck and just threw them into the back of the truck. A few months ago we went down to Arkansas and I put a tri-mag mount on top of the wife's Outback. There is no sun roof. I always add ground radials connected to the mount. The radials were roughly cut for 20m and run down each side and into the car and stuffed under the back seat. I did not put my meter on the Hamsticks due to lack of time before we left. The KX2 tuned it just fine and I worked many POTA stations on the trip. Try it with ground radials Tracy.
I remember adding coax segments on the 20-40M Hamsticks when installing on my 2023 Silverado 2500HD to bring down the SWR from 2.5 to 1.5:1 for my POTA Activations. I attributed it to only using a 5" magnet instead of the powerful 3-magnet versions. That was just a guess, but it appeared the longer coax made a better counterpoise. I regretted dropping my magnet in Colorado, every tiny piece of gravel with magnetite magnetic characteristics was almost impossible to remove without a lot of patience & perseverance, lol. Cheers, Davey --KU9L
I using a telescoping whip as the stinger for my ham sticks this allows me to use one stinger for all two (but soon to be more, hopefully) of my ham sticks. I also mark in the fiber glass rod what length the whip needs to be depending on car and if I am going digital or voice. I just made a recent short on my channel as a quick demo
I use the bigger metal triple mount behind the cab of my F150 on a steel toolbox. Not ideal behind the cab, but everything from 20-10m tunes almost flat. My sticks are screwed directly into the threaded mount, no extra hardwares, no adapters or springs. I can pretty easily tune my 10m stick down into 11m if I want. Interesting to see your tests and results. Keep on!
I have heard that the sticks expect to use the top of the vehicle as a counterpoise, thus not performing as well if they aren't directly connected to it on the shielding side near the base of the antenna. I have not done enough experimentation to confirm this one way or another. Just passing along what I've heard. Cheers.
Very interesting. I have both a dodge ram and a Toyota highlander that I use the same components on. I use my hamsticks quit often. My Toyota highlander has a sunroof and roof racks. I place my magmount directly in the middle from the sunroof to the rear and side to side. I have not had this issue. Makes me question a couple of things. 1. Is your magmount coupling good? 2. Is there something different about a Subaru? Different metals within the roof structure? Or is there wiring in the roof causing an issue down stream? Just curious and would like to learn from this. First time I have heard of this issue. N2NRL
We were experimenting with an Outback with roof rack and sunroof and found on a couple hamsticks that opening the hatch helped with the tuning. I don’t remember the exact numbers, it wasn’t my Outback or radios, but we did get all the sticks we tried to tune to usable. Since that time they have swapped to the triple magnet and spring with reports of much better tuning but each still needs a different roof location for tuning.
I've never had much use for Hamsticks. They are under performers. I prefer Hustler mobile antennas. Your problem is more likely lack of bonding to the body. The magnet mount does not give enough coupling. It is almost always necessary to add a physical bond with a wire to the car body. In some cases without a solid bond, you can get an RF tickle from your mic while transmitting if it has any metal in it. That's been my experience.
It might not matter, but isn't the roof of those aluminum? Looked pretty stable in the rhino position, so maybe not. But possibly not coupling efficiently with the chassis due to lack of inductive coupling (if that's true). Just a thought. One of the guys in our local club runs a Subaru and can't do mag mounts. I run ham sticks on an MFJ triple mag mount (80-20, mostly 80) set on the back third, right behind a 3' sunroof, that's never been an issue, but I have a steel roof (older X3 BMW). I normally do run 2 other antennas at the same time (ATAS & 60" 2M), but that doesn't seem to affect it much. Thanks for posting, always good to see hams getting out of the shack! 73
Was wondering if you bonded all of the body panels in your Subaru. It sounds like you have a ground plane problem, other than just positioning. I have a truck with removable hamstick mount and permanent ATAS 120. I kept adding bonding straps and the swr's got lower. Ended up with 25, bonding straps, bonding the hood, doors, pickup bed , tail gate, and muffler all to each other and to the frame. With a mag mount you need to bond it directly to the ground plane you create, also. It's a LOT of work, especially for a low clearance vehicle. I get very good signal reports and a lot of contacts are impressed, especially coming from a mobile.
I've played around with mag-mounts and ham sticks and 17 foot telescoping whips. My 17 foot whips always has a higher resonant frequency when on a mag-mount on vehicle. Ground mounted with radials, the resonant frequency is lower and where I would expect it. I believe this is due to losses created by the mag-mount and how it capacitively couples with the body of the vehicle. Just like you did with the spring, I use a coil to make my antenna a little longer and the problem is solved. The mag mount is probably coupling better at different points on your car due to the vehicle construction and better still on Mike's car.
DX commander showed that sometimes you should ground the roof as those can be isolated from the car. Also Ham Radio Tube was experimenting with ham sticks and discovered that 40m one is really hard to adjust. He used few ferrites to make it work. Just go to their channels and look for it. I managed to make those work but I don’t use mag mounts with my car. 73!
Makes sense of a situation I had. Old SUV was a solid roof, new SUV, has a huge sun roof. SWR was fine on old SUV but same issue you're having with yours with my new SUV.
Yeah, roof area matters. Another local ham to me tried to duplicate what I've done on my Honda Element with a trim-mag mount and some ham sticks (same as I use). On the roof of their pick-up truck, they couldn't get the ham sticks to get a good SWR... Vehicle roofs matter so much. Good info to know. 73!
The coil is lengthening the antenna, not just raising it. I experienced some issues when operating mobile with a mag mount and Hamsticks. Down to 20M, they worked pretty well, but on 40M, not so much. Going from a single magnet mount to a triple magnet mount helped, probably because of the additional capacitance to the car. I finally screw a tab into my car body and used copper braid to the antenna ground on the mag mount and that fixed the problem. Of course, at the time, I was just using an SWR meter, not an antenna analyzer, 40 years ago. Still your results are interesting.
I should have mentioned this in the video, but there is a braided wire in the center of the spring which connects the 3/8ths by 24 mounting point to the socket at the top of the spring. So yes, the length of the antenna is increased by about 3 inches. What i found interesting was that even that additional length was not enough to bring the antenna system into resonance. Thank you for sharing your experience.
On top of placement, which is relevant to all roof mounts types, be advised that MAGNETIC roof mounts don't couple efficiently for transmitting. Magnetic roof mounts are fine for receiving / scanning as there is no SWR.
Your biggest problem is the Comet mag mount, which I also own. The thick rubber pad on the bottom inhibits proper capacitive coupling. Try either removing the pad or use one of those three magnet mounts.
Hi Thanks for the info. Question- if you were not planning to drive with the magmount - wouldn't you be able to place the mount on the car hood. I assume this would allow it to be more resonant ?
Would be nice to know and I have seen a significant between a regular mag mount and a tri-mag mount, usually is there is a difference it gets higher the lower in frequency you go. Would have nice to see what clipping a few bundles of radials did to it. KF0LZX
Tracy do you run your coax around the car? My coax is long enough to go right around the car and back to the take off point. This gives a good ground coupling and my SWR is always at its best. The coax is best placed outside the line of the car slightly not under the body. try it if you haven't already.
@@OutdoorsOnTheAir ok yes, my coax for use with my magmount vertical, is about 18m long. It's long enough to come off the roof, drop to the ground, then go all the way around the car on the ground and return to the point it where it starts. i.e. the entire circumference of the car. It also is run about 2 feet outside the perimeter of the car so it can always see the sky - so to speak. I find the SWR is always good with that config. If on the other hand I only use about 6ft of coax and stand beside the car, the SWR is very poor. My car is similar to your wrt roof racks - it's a Mazda 6 station wagon. I would say this is because the coax provides a good ground coupling and improves the coupling provided by the mount on the car body in this config. Many others have argued that you need a lot of coax for a magmount setup. This has proven correct for me. Give it a go. Can't hurt to try.
Get a different mag mount with a 3/8-24 to directly mount your ham stick. I also drive a subaru outback and do not have any such problems when in the field. Also, get the adapter to run 2 of them as a horizontal dipole. I mount mine on 4 - 5 foot tv mast sections as a (hand) rotatable dipole. The 40 meter ones are too short to work well, less than 1/3 of full size. Yes, they do tune a bit differently that way. Counterpoise resonance issue. Oh, no. The roof rack dont matter. Put your mag mount in the center of the roof. Jerry wa2omu
I have ham sticks on roof of my Ford Expedition with a mag mount. And a roof rack and get perfect swr. And I have two sunroof’s. But what I also did was run a ground wire from the ground of the antenna along the coax and then bonded the other end of the wire to the car body. Swr problems solved.
In general HF mobile antennas require direct bonding to the body using a wire or strap. One sometimes can get enough capacitance by using a mag mount with three magnets or attaching a long wire strap to the base and taping the strap to the body. The Idea in to increase the surface area of capacitive contact between the antenna base and the body. Your observations have been known for decades. Direct bonding works better.
I think that with the sunroof, you might be coupling to the edges of the sunroof itself and that it is acting like a slot antenna. Regarding the spring, is it acting like a spacer, changing the capacitance coupling, or is it acting like an inductor? It might be interesting to stick some thin plastic between the coils of the spring to see what changes. Who knows? You might even be able to bring the antenna to resonance with this makeshift "variable" inductor! 😂Love to see a follow-up video. All the Best! 73 DE W8LV BILL (W8LV/VE3 pre pandemic)
Thank you for your thought-provoking comment, Bill! As far as the spring goes, there is a braided wire in the center that makes the connection from the 3/8ths x 24 plug at the bottom and the socket at the top so adding the plastic wouldn't make a difference. 73 from VE3TWM!
When you put the spring in there you made it longer! That changes where the antenna is tuned. It is not a coil! It is a spring! There is a wire inside that goes from one end to the other of the spring! 73 W4DES
@@OutdoorsOnTheAir Not sure if everyone watching the video knows. to someone that has not seen the inside of spring don't know that there is a wire in there.
It is most important to ground radio as close to body / frame work along with straps on mag mount to the screws that hold down the luggage rack … never trust the capacitive coupling effect of the magnet … WB0NXG
That spring will help the fiberglass live longer too because eventually all the hamsticks break in the fiberglass and become no good. Tuning is just a part of mobile installs. The ultimate antenna rule: What WORKS works.
Quite possible that Hamsticks are made to be used with the springs. CB whip antennas come in 102 inch lengths. The quarter wave resonance on CB is 108 inches. So, the spring must be used in conjunction with the whip to arrive at the correct resonant length, which is what you’re seeing.
There is no substitute for the zero resistance of the base of each antenna to the body of the car. Such a magnetic base placed on the roof is not very effective.
The spring adds physical length. Thus lowering the resonant freq.
Also, the stinger should never extend down into the coil area.
True, however the resonant frequency on a Hamstick unaffected by near field objects should be lower than what I got if the only factor was length.
What happens if the singer extends down into the coil?
@@stuarthall3874it de-tunes the coil portion. I think you only have about 3 inches to insert the stinger before it drops into the coiled section.
I bought several antennas, mounts, studs, springs, and cables to test with a RigExpert(55) meter. Tired of some local ‘experts’ opinions that seem more about my wallet than my radios. Have used the meter to move a coworkers mag mount and dialed in great SWR with a cheap antenna . The RigExpert confused me at first but I’m liking it now.
@@stuarthall3874 It will create heat and can damage the coil!
I drive an Outback and I use the Shark HF sticks. I had the exact same problem you are experiencing. But I don't think its the roof rack as much as it is the poor capacitive coupling of the magnet base. They way I solved the problem was to add 25 feet of coax to my mag mount. I believe this creates a counterpoise of sorts as the resonant point of the antenna drops right into the band. I've done this on vehicles both with and without roof racks with similar results.
Hi Michael, always nice to hear from you! Thank you for this information, I'll share it in an upcoming video.
Excellent hamvestigation! That's my new word now!
Nice one, Steve! Get that puppy trademarked😀
What if by adding the spring to the base of the antenna you've actually added physical and electrical length to the antenna? You were resonating high in frequency which is indicative of an antenna which is too short for the desired resonant frequency. But when you added the spring you added both mechanical and electrical length to the antenna making the antenna longer which lowers the resonant frequency of the antenna. What is inside that spring to connect the antennas radiating element to the center conductor of the coax? My guess is bare copper wire. The couple inches of copper wire added to the electrical length of the antenna is certainly long enough to lower the resonant frequency of the antenna. Most certainly the metal within the roof rack has some influence on the antenna as it is less than 1/4 wave away from the antenna. While there is a null immediately below the vertical dipole, the metal frame of the roof rack is 90 degrees from the feed point of the antenna. I imagine that the lobe of the vertical antenna is quite wide at the feed point, perhaps wide enough to be influenced by the roof rack.
I use a tri mag mount and Ham Sticks from MFJ (600watts) on my Ram and used a Nano VNA and I was able to tune them to 1.1.
40M, 20M, 10M Ham Sticks
Tri mags tend to be more robust I found 👍
Absolutely right! My tri-mag mount (Tram) tunes everything so much better than a single mag. The extra capacitive coupling to the roof metal makes a BIG difference ... averaging SWR of 1.1 to 1.4:1 at resonance on all HF bands. Even when I moved it around the roof, there is very little difference in performance. I only use a single mag mount for VHF/UHF. I don't recommend HF on a single mag mount for optimal results 😀 73 KJ6ER
Hi there. i have on occasions experienced similar unexplained problems. There is a likelihood that your VSWR readings are being affected by common mode currents. Try installing a ferrite core choke near the base feed point of the antenna. Sometimes a choke at feed point to the transceiver will also correct this problem. Give it a try. 73 Peter G3OJV
HI Peter, nice to hear from you! Thank you for sharing this information. I'll refer to it in a follow up video. 73 from VE3TWM.
Interesting experiment! One variable not discussed but is an elephant in the room is that the mag mount capacitively couples the ground plane. It would be interesting to note how a solid electromechanical connection via a mount drilled into the roof would affect resonance. Another thing to consider is... since there is no good electromechanical connection to the ground plane, the coax is also acting as a non resonant counterpoise, and it ALSO is capacitively coupled to the body of the car as you move the target around on the roof. This experiment DOES prove how dubious the ground plane is when capacitively coupled via a magnetic mount and when there is not solid connection of the antenna to the ground plane. You may wish to further test your conclusions with these additional considerations. Best 73's Dan. K1YPB - On the air since 1962.
Great points, Dan! 73 from VE3TWM.
I was thinking of putting a “magic carpet “ between my magnet mount and car roof
100% correct (magnetic mounts). If it was just for receiving / scanning it wouldn't matter.
@@VA7AYGhmm dubious, but in the ham tradition definitely worthy of experimentation.
When I first started messing with whip antennas on top of cars using my MFJ whip on a magnetic mount, I noticed that by moving my coax around I would get unpredictable results. I wrapped my coax around a toroid as many turns as I could fit (they certainly give you enough coax for mobile use) as close to the antenna as I could. This eliminated common mode currents and interaction with the car body. I haven't had a problem tuning my antenna since making the modification.
KE8RWW, 73.
Very helpful, thank you and 73 from VE3TWM!
Thank you for this. Looking at what you've found, I think I'll use my Wolf River Coils Mimi antenna not only as a base but also as a way to tune my hamsticks more precisely Only for my 75 meter stick.i can use the WRC mini as a stand alone for the other bands
I've used a Buddipole coil along with a 30" steel whip to run many bands while mobile. Good luck!
You make a great engineer. Thanks for work.
Thank you!
I use hamsticks for my POTA activations. I started with a 2014 Dodge Caravan, and a 5" mag-mount, and the hamsticks I have cover 10m through 75m. This set up was used for 3 years and 390 successful POTA activations. Last August I traded in the van and bought a 2022 Nissan Frontier. I was worried that the much smaller roof of the truck would detune the hamsticks. What I discovered is that nothing changed, the hamsticks still tune the way they did on the old vehicle, and I'm now up to 465 successful activations. I operate exclusively SSB or CW QRP. Thanks for the interesting video and lots of food for thought.
Thank you for sharing what you have encountered!
Hello chap, I had similar issues a few years back as my Volvo has roof rail too. I found that putting a choke in line made a big difference, also, adding capacitive strip to the mag-mount too solved all the issues. Allan G6HPR
Thank you for the tip, Allan!
Hi, Just wondered if you thought of using a piece of faraday cloth and laying it on the vehicle roof under the mag mount? It's very pliable and would not scratch paint finish. It seems to be an effective ground plane and is becoming popular with hams operating portable, replacing radials and metal screens. Good luck . VE3WNS
Interesting idea, thank you Norm!
Good experiment Tracy! Very interesting outcome! Hamsticks seem to be notorious for difficulty in tuning on anything anywhere. Some have had success cutting the whips down a few inches. I used a 10,20, and 40m MFJ Hamstick on the top center of my extended cargo van. No rack rails and no sunroof. Right out of the package they all 3 were resonant somewhere within the band they were intended for. I put the same Hamsticks on top of my KIA Soul with no racks or sunroof and couldn’t get them to tune anywhere near their intended band. After hours of trying I gave up. I might try cutting the whips down and see if that helps. 🤔
I would have liked to see you compare the front hood to the roof of your vehicle. More metal, but perhaps less coupling with the rest of the vehicle. It was also suggested to me when I first started using hamsticks, to go to a tri-magnet mount. I can only say that I have had little or no problem tuning my collection of hamsticks and Hustlers. I next ran a section of insulated wire, electrically connected to the magmount to a bolt in the hinge of one of my rear doors. Having moved from an suv to a truck and camper, I next bought a 3' extension to lift my hamstick up by 3 feet. The rationale was that I was getting some reaction between the antenna and the camper . All good so far, and no problem tuning. Thx for the great vid. Brent
Hi Brent, thank you for your comment. The hood of the Outback is not magnetic or I would have shown that configuration. I like your idea of using an extension and a connection to the car battery.
hi Tracy. nice experiment. have you tried to join a light telescopic antenna with a crocodile clip and put it at the tip of the stick, shorten and extend it to see the difference in results? most people i know use those antennas just for listening on the move, but when they want to do QSOs they park and add radials. I saw michael's comment about mag mount capacitance coupling and went to watch his video. I have a couple of ham sticks but never used them for mobile. only as a rigid dipole.
Try mounting the antenna on the cross member, it may improve the SWR, I have no idea if it will or not, but it may add a little more height.
Thank you for the suggestion! I have not been able to find a commercial mount that will fit the Outbacks' crossbar yet.
Tracy you need to put a feed line choke between the rig expert and the antenna . Secondly the adapter has raised the base of the antenna off the magnet mount and the magnet needs to be a minimum of 5" diameter for best results .
Thank you...I'm going to try this!
I used to use Hamsticks on an F-150. I cut a 20m and 40m radial and ran them to the back of the truck and just threw them into the back of the truck. A few months ago we went down to Arkansas and I put a tri-mag mount on top of the wife's Outback. There is no sun roof. I always add ground radials connected to the mount. The radials were roughly cut for 20m and run down each side and into the car and stuffed under the back seat. I did not put my meter on the Hamsticks due to lack of time before we left. The KX2 tuned it just fine and I worked many POTA stations on the trip. Try it with ground radials Tracy.
I remember adding coax segments on the 20-40M Hamsticks when installing on my 2023 Silverado 2500HD to bring down the SWR from 2.5 to 1.5:1 for my POTA Activations. I attributed it to only using a 5" magnet instead of the powerful 3-magnet versions. That was just a guess, but it appeared the longer coax made a better counterpoise. I regretted dropping my magnet in Colorado, every tiny piece of gravel with magnetite magnetic characteristics was almost impossible to remove without a lot of patience & perseverance, lol. Cheers, Davey --KU9L
Thank you for sharing your experience, Davey!
I using a telescoping whip as the stinger for my ham sticks this allows me to use one stinger for all two (but soon to be more, hopefully) of my ham sticks. I also mark in the fiber glass rod what length the whip needs to be depending on car and if I am going digital or voice. I just made a recent short on my channel as a quick demo
Great stuff! I hope people reading this check out your interesting experiment.
I use the bigger metal triple mount behind the cab of my F150 on a steel toolbox. Not ideal behind the cab, but everything from 20-10m tunes almost flat. My sticks are screwed directly into the threaded mount, no extra hardwares, no adapters or springs. I can pretty easily tune my 10m stick down into 11m if I want. Interesting to see your tests and results. Keep on!
I have heard that the sticks expect to use the top of the vehicle as a counterpoise, thus not performing as well if they aren't directly connected to it on the shielding side near the base of the antenna. I have not done enough experimentation to confirm this one way or another. Just passing along what I've heard. Cheers.
Very interesting. I have both a dodge ram and a Toyota highlander that I use the same components on. I use my hamsticks quit often. My Toyota highlander has a sunroof and roof racks. I place my magmount directly in the middle from the sunroof to the rear and side to side. I have not had this issue. Makes me question a couple of things. 1. Is your magmount coupling good?
2. Is there something different about a Subaru? Different metals within the roof structure? Or is there wiring in the roof causing an issue down stream? Just curious and would like to learn from this. First time I have heard of this issue.
N2NRL
We were experimenting with an Outback with roof rack and sunroof and found on a couple hamsticks that opening the hatch helped with the tuning. I don’t remember the exact numbers, it wasn’t my Outback or radios, but we did get all the sticks we tried to tune to usable. Since that time they have swapped to the triple magnet and spring with reports of much better tuning but each still needs a different roof location for tuning.
That's nuts, opening the hatch helped??? Thank you for sharing!
@@OutdoorsOnTheAir yes, opening the hatch helped on a couple hamsticks.
I've never had much use for Hamsticks. They are under performers. I prefer Hustler mobile antennas.
Your problem is more likely lack of bonding to the body. The magnet mount does not give enough coupling. It is almost always necessary to add a physical bond with a wire to the car body. In some cases without a solid bond, you can get an RF tickle from your mic while transmitting if it has any metal in it. That's been my experience.
Thx for that comment. I had a friend that used a 40 meter hustler with a 600 watt amplifier. He preferred them also.
Did you try testing the antenna with spring mounted back at the center of the roof? What reading did you get?
It might not matter, but isn't the roof of those aluminum? Looked pretty stable in the rhino position, so maybe not. But possibly not coupling efficiently with the chassis due to lack of inductive coupling (if that's true). Just a thought. One of the guys in our local club runs a Subaru and can't do mag mounts. I run ham sticks on an MFJ triple mag mount (80-20, mostly 80) set on the back third, right behind a 3' sunroof, that's never been an issue, but I have a steel roof (older X3 BMW). I normally do run 2 other antennas at the same time (ATAS & 60" 2M), but that doesn't seem to affect it much. Thanks for posting, always good to see hams getting out of the shack! 73
Was wondering if you bonded all of the body panels in your Subaru. It sounds like you have a ground plane problem, other than just positioning. I have a truck with removable hamstick mount and permanent ATAS 120. I kept adding bonding straps and the swr's got lower. Ended up with 25, bonding straps, bonding the hood, doors, pickup bed , tail gate, and muffler all to each other and to the frame. With a mag mount you need to bond it directly to the ground plane you create, also. It's a LOT of work, especially for a low clearance vehicle. I get very good signal reports and a lot of contacts are impressed, especially coming from a mobile.
I did no bonding on the car. Thank you for sharing your experience!
Wondering how it would work on the front hood? I have an outback and was thinking about the mag mount + ham stick for pota
The front hood of my 2017 Outback is not magnetic. Of course, I could try a lip mount with a counterpoise or grounded to the car frame.
Nice analysis and insight. Thanks.
I've played around with mag-mounts and ham sticks and 17 foot telescoping whips. My 17 foot whips always has a higher resonant frequency when on a mag-mount on vehicle. Ground mounted with radials, the resonant frequency is lower and where I would expect it. I believe this is due to losses created by the mag-mount and how it capacitively couples with the body of the vehicle. Just like you did with the spring, I use a coil to make my antenna a little longer and the problem is solved. The mag mount is probably coupling better at different points on your car due to the vehicle construction and better still on Mike's car.
DX commander showed that sometimes you should ground the roof as those can be isolated from the car. Also Ham Radio Tube was experimenting with ham sticks and discovered that 40m one is really hard to adjust. He used few ferrites to make it work. Just go to their channels and look for it. I managed to make those work but I don’t use mag mounts with my car. 73!
Makes sense of a situation I had. Old SUV was a solid roof, new SUV, has a huge sun roof. SWR was fine on old SUV but same issue you're having with yours with my new SUV.
My Nissan Rogue has a big sunroof and racks. I put the triple mag mount on the rear driver or passenger side and get a good match.
Thank you for sharing this. I keep hearing that regarding the triple mag mount.
Yeah, roof area matters. Another local ham to me tried to duplicate what I've done on my Honda Element with a trim-mag mount and some ham sticks (same as I use). On the roof of their pick-up truck, they couldn't get the ham sticks to get a good SWR... Vehicle roofs matter so much. Good info to know. 73!
Thank you for sharing your experience and 73 from VE3TWM!
the problem is probably the magnetic base, try using a different one for subsequent measurements
Interesting! Thank you for your suggestion.
The coil is lengthening the antenna, not just raising it. I experienced some issues when operating mobile with a mag mount and Hamsticks. Down to 20M, they worked pretty well, but on 40M, not so much. Going from a single magnet mount to a triple magnet mount helped, probably because of the additional capacitance to the car. I finally screw a tab into my car body and used copper braid to the antenna ground on the mag mount and that fixed the problem. Of course, at the time, I was just using an SWR meter, not an antenna analyzer, 40 years ago. Still your results are interesting.
I should have mentioned this in the video, but there is a braided wire in the center of the spring which connects the 3/8ths by 24 mounting point to the socket at the top of the spring. So yes, the length of the antenna is increased by about 3 inches. What i found interesting was that even that additional length was not enough to bring the antenna system into resonance. Thank you for sharing your experience.
Try a triple mag mount
Before antenna analyzers, we commonly added a capacitor/inductance coil at the base of the antenna to get better matching.
Thank you for this!
On top of placement, which is relevant to all roof mounts types, be advised that MAGNETIC roof mounts don't couple efficiently for transmitting. Magnetic roof mounts are fine for receiving / scanning as there is no SWR.
Good advice, especially on 20m and below!
Your biggest problem is the Comet mag mount, which I also own. The thick rubber pad on the bottom inhibits proper capacitive coupling. Try either removing the pad or use one of those three magnet mounts.
Hi Thanks for the info.
Question- if you were not planning to drive with the magmount - wouldn't you be able to place the mount on the car hood. I assume this would allow it to be more resonant ?
Great question...yes but the hood of the Outback is not magnetic.
Have you tried using it on the hood or the hatch lid when open? If so, did it have any positive or negative effect?
No, I have not! That's an interesting question, I'll have to give it a try.
Would be nice to know and I have seen a significant between a regular mag mount and a tri-mag mount, usually is there is a difference it gets higher the lower in frequency you go.
Would have nice to see what clipping a few bundles of radials did to it. KF0LZX
Tracy do you run your coax around the car? My coax is long enough to go right around the car and back to the take off point. This gives a good ground coupling and my SWR is always at its best. The coax is best placed outside the line of the car slightly not under the body. try it if you haven't already.
Thank you for your interesting comment! Could you be more descriptive of what you are referring to, I've having difficulty picturing it.
@@OutdoorsOnTheAir ok yes, my coax for use with my magmount vertical, is about 18m long. It's long enough to come off the roof, drop to the ground, then go all the way around the car on the ground and return to the point it where it starts. i.e. the entire circumference of the car. It also is run about 2 feet outside the perimeter of the car so it can always see the sky - so to speak. I find the SWR is always good with that config. If on the other hand I only use about 6ft of coax and stand beside the car, the SWR is very poor. My car is similar to your wrt roof racks - it's a Mazda 6 station wagon. I would say this is because the coax provides a good ground coupling and improves the coupling provided by the mount on the car body in this config. Many others have argued that you need a lot of coax for a magmount setup. This has proven correct for me. Give it a go. Can't hurt to try.
Did adjusting the stinger change anything or make it worse? I found that hamsticks can be pretty finicky to make them resonant. 73 de K2CJB
Hi Chris, adjusting the stinger did move the resonant point, but not by much. 73 my friend!
Get a different mag mount with a 3/8-24 to directly mount your ham stick. I also drive a subaru outback and do not have any such problems when in the field. Also, get the adapter to run 2 of them as a horizontal dipole. I mount mine on 4 - 5 foot tv mast sections as a (hand) rotatable dipole. The 40 meter ones are too short to work well, less than 1/3 of full size. Yes, they do tune a bit differently that way. Counterpoise resonance issue. Oh, no. The roof rack dont matter. Put your mag mount in the center of the roof. Jerry wa2omu
MAYBE TRY SOME FARADAY CLOTH UNDER THE MAG MOUNT
I have ham sticks on roof of my Ford Expedition with a mag mount. And a roof rack and get perfect swr. And I have two sunroof’s. But what I also did was run a ground wire from the ground of the antenna along the coax and then bonded the other end of the wire to the car body. Swr problems solved.
In general HF mobile antennas require direct bonding to the body using a wire or strap. One sometimes can get enough capacitance by using a mag mount with three magnets or attaching a long wire strap to the base and taping the strap to the body. The Idea in to increase the surface area of capacitive contact between the antenna base and the body. Your observations have been known for decades. Direct bonding works better.
It's funny how many things that have been known for decades are not common knowledge.
try making sure the metal on the roof racks are grounded
Interesting! Ty for the info
It’s more of a unicorn mount than a rhinoceros. 😂
My mercedes is aluminum and mag mounts won't work, plus my roof is glass
I think that with the sunroof, you might be coupling to the edges of the sunroof itself and that it is acting like a slot antenna. Regarding the spring, is it acting like a spacer, changing the capacitance coupling, or is it acting like an inductor? It might be interesting to stick some thin plastic between the coils of the spring to see what changes. Who knows? You might even be able to bring the antenna to resonance with this makeshift "variable" inductor! 😂Love to see a follow-up video. All the Best! 73 DE W8LV BILL (W8LV/VE3 pre pandemic)
Thank you for your thought-provoking comment, Bill! As far as the spring goes, there is a braided wire in the center that makes the connection from the 3/8ths x 24 plug at the bottom and the socket at the top so adding the plastic wouldn't make a difference. 73 from VE3TWM!
When you put the spring in there you made it longer! That changes where the antenna is tuned. It is not a coil! It is a spring! There is a wire inside that goes from one end to the other of the spring! 73 W4DES
When I used the word "coil" I misspoke. I do understand the difference.
@@OutdoorsOnTheAir Not sure if everyone watching the video knows. to someone that has not seen the inside of spring don't know that there is a wire in there.
coil or spring ??
spring
It is most important to ground radio as close to body / frame work along with straps on mag mount to the screws that hold down the luggage rack … never trust the capacitive coupling effect of the magnet … WB0NXG
That spring will help the fiberglass live longer too because eventually all the hamsticks break in the fiberglass and become no good. Tuning is just a part of mobile installs. The ultimate antenna rule: What WORKS works.
Thanks!
Thank you very much! 73 from VE3TWM.
That's no rhinoceros--it's a narwhal, LOL. Nice hamvestigation!
😂
"Shouldn't" is what the head of the committee thinks, lol
Interesting🤔!
Quite possible that Hamsticks are made to be used with the springs. CB whip antennas come in 102 inch lengths. The quarter wave resonance on CB is 108 inches. So, the spring must be used in conjunction with the whip to arrive at the correct resonant length, which is what you’re seeing.
There is no substitute for the zero resistance of the base of each antenna to the body of the car. Such a magnetic base placed on the roof is not very effective.
Thanks!
Thank you very much! 73 from VE3TWM.