CB Radio Beginners Guide. How to diagnose and fix a high SWR.
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- เผยแพร่เมื่อ 5 ก.ค. 2024
- A high SWR will effect us all at some time during the hobby of radio. In this video i explain the basics for the beginner to track down the problem. Also inc is my own journey to resolve a creeping SWR problem. Please leave your own helpful suggestions in the comments.
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Hey Fred and everyone out there, let me inform you on a bit of information that I was told by my RF Engineer at work. When checking SWR on a system with a length of cable that exceeds lets say 15 feet, the cable can absorb some of the RF power and mask the reflection coming back to the source. This means at the legal 4 watts of CB power you may not be able to measure the SWR reliably due to the cable loss absorbing the reflection going back to the SWR meter. Even though cable losses are much less at 27MHZ as compared to 467MHZ I found this to be true with my GMRS setup as I use a 50 foot cable to my antenna and at low power (5 watts) I am reading a perfect 1.00 on the SWR meter however at high power (50 watts) I read a maximum of 1.64 on the SWR which is more accurate due to the fact that the higher power negates the cable loss in my system. If you were able to boost the power output (just for brief testing purposes) you would be able to get a more accurate measurement of SWR in your setup. Thank You for your many informative videos!
Also don't trust antenna only
The coax can then bite you in behind always include the" system" not the individual " I have seen antenna at 1.1 self coax with dummy load at end 1.1
Both with and without power combined 1.3 powered 200wstt level 1.5 weird ain't it individual elements more or less perfect combined increases more jumpers also mean points of future fails 😔. You also need to keep velocity of cables in mind
I was told the short when antenna is connected is often due to matching transformer in base of aerial, I had this with my 1/2 wave silver rod. Threw me for a minute. In the end discovered it was moisture ingress in the aerial. Dismantled, dried out, re-assembled and made sure I taped up the joints to prevent reoccurrence.
Excellent information as always Fred , thank you for sharing .
Good info for the new stations setting up'
56CT004🏴☠
Thank the Lord you didnt use the phrase SWAR. That pisses me right off about some other channels i watch. And yes i know the background, im a brit too and used to annoy the hell out of me in the 80s too lol
Fred just watched this video and yes it's a bit of a headache but like you said, just got to go through it in a logical way, thanks for all your help, and yes we do need it every now and then, like it's not just me, anyway this is the weekend I'm putting my ARIEL UP , and Got everything I need Touchwood.just neighbours I need to be careful about, but I'm think I'm ok, so it's going to be very wired to hear you on the CB, BUT even better to get a copy, thanks again FRED and speak soon, Alan from LUTON,but I'm in Leighton buzzard now.🍻💯👍
Hi Alan. Leighton Buzzard is a far bit out for me to get a good contact but you never know on SSB.
Frid in the shed your TH-cam videos are awesome my friend
Fantastic video
Very good info thanks for that, could you do a video on how to wire up a Amp.👍
I love your videos Fred. Keep em coming mate
SWR is dependable from activity of HARP if is on swr going hi. Just check ground yours antenna.
Frid in the shed I learn lot from you about bying cb radios and antennas for cb radios and power supplys for cb radios my friend
Stay safe bud and thanks.
BTW: It's self-amalgamating tape. 👍
Just been looking at some of your earlier burner videos, where youve got the EM27 hooked into a zetagi .. you made the point about over driving the amp, but SWR is equally or possibly more likely to kill linears.
I blew up a 203p quite spectacularly!
Another point to make is antennas are often sold as "pre calibrated" this is also a rarity. Case in point I have the Sirio 5000 performer on my car, bought as calibrated.
In order to get my swr down, I had to have the whip at its lowest setting AND snip about 2 inches off the top of the whip!
wat i found out is that for me,it depends wat radio i use like for example when i use the 6900 i have mostly 1.7 or more swr (internal meter) but when i use the president lincoln 1 for example i have about 1,2 1,3
Good video fred as pur use .hope your well
Thanks, you too!
Hello Fred people with even 50 years of operation still have swr issues I see what acts like shorts after changing 4 jumpers in shack ( pre made and store bought ) just touching the backside of connectors a nd both swr and receive shoot both directions touch again with slight pressure comes back to 1.1 my volt meter finds no short but physical and slight move skywards!!
I have other issues of velocity factor changes in shack using multi gauge size coaxes rg8x or 213 and 5-6' lengths hold good swr but show up as changes in swing levels of s meter on radio which uses multi function swr power and receive measures separate meter pep shows larger swing as velocity changes but standard swr no change
I am trying pre. Made 213 5' jumpers with amphenol fittings ( don't like the compression crimp on pll259 other issue I noticed tightening pl259 just below finger tight get to and just past finger tight swr and receive again
Ho Fred. A quick question. Do patch leads or extension cables give you less signal. Like if I have a patch lead from a burner then onto a switching box. Thanks
It does add up if you use too many. Best is a straight run from the antenna to the radio.
Hi Fred coax length should make no difference to swr its a myth.. reckon it was a connection issue...often what happens when people solder their own pl259 on is they do a crap job and get a blob of solder on the outside of centre pin ...this ends up then being a tight fit in the so259 problem is then it forces the centre blades in the so part to open up with a result that when you unplug and reconnect the centre pin fails to make a good connection and will lead to high swr but in your case it sounds like the contract in the switch box ...those others you showed i have never had an issue with ! Maybe your using in damp conditions ? Usually best to have an earth connection to the switch to ground out the unused connection those other switches have very low swr insertion loss and well over 55db rejection to the next port ...my pennies worth lol
Best wishes Mac
Great advice on the soldering.
Frid in the shed iam thinking about getting my Grms license
"REF" on the meter stands for reflected BTW
Yes thanks. I ve forgotten thatbefore.
Did you buy that Alinco off Transmission 1 Fred? Boxed? Lots of Years ago now As i sold mine on there and im sure the guy was called Fred. Mine was the 77(e)
Hi. No i got it from a Ham on ebay.
@@CB-RADIO-UK ah worth a shot they aren't a common radio.
I have had this hi swr problem I have a crt ss9900 tryed cutting a 1/4 inch at a time mag mount siro5000 antenna I just don’t want to keep cutting the antenna down getting reading of ch 1 at 3.4ch40 at 4.1 checked for shorts no shorts at all used various swr meters but up pops the hi swr on screen on radio hi swr with in 2 seconds when I key the mike any help rpm yourself or your subscribers would very much appreciated should also had this radio about 4 months also my first Cb radio.
Hi. The whip section really should not need cutting for CB. Normally with magmounts other than a bad antenna high swr comes down to lack of ground plane. The magnet needs to be firmly attached to an expanse of metal to work. This would normally be a car roof. Are you using it at home ?
I have to attach the mag mount on the side of my Mazda bongo hi top as the hi top is made from fiberglass also mat Ian ask should I turn off the internal swr if I am using the external swr and power meter same as the one in your video swr-120 any advice appreciated.
@@CB-RADIO-UK here in germany we have 80 channels cb. Channel 1 is 26,965 to 40 27, 405 and channel 41 is 26,565 to 80 26,955.
Ps just to add a coil won't effect swr hence why we deliberately put a coil in the coax ..ie a dirty balun 👍
Question: The clarifier on this radio make the knob klikklik noises or is it free from kliks? greetings 19DCG123
No the CRT 6900 has a stepped clicky control.
@@CB-RADIO-UK alinco dx-10/k-po dx5000 are all the same radio"s but have they all clicky controle?????
Fred's got rats 🐀 🤣 😮.
Actually do have a rat problem in the garden. Have had for a few years now :-(
U need a rat traps 😅
@@CB-RADIO-UK you need a air rifle. Another nice hobby. Go hunting.
Lower the ring's don't use a tuner!
Tuners are no good ! You are only fooling yourself and your antenna. Strive for a low swr and forget about the tuner.
99's come pre tuned at 27.205,aim for the lowest SWR at the frequency most used.