Mobile False swr readings

[SlackGirl]

Hii can anyone help me with this swr meter issue maybe. My radio have a built in meter and it shows a low swr. I wanted to double check so I connected an external meter.

When I did that, the external meter show a too high swr, and the radio now also shows a high swr that matches the external meter.

I adjusted the antenna until both the internal and external meters showed a low swr and when testing on different channels they did match. So I was satisfied and plugged the antenna back into the radio and packed away my meter, but all of a sudden the radio shows a high swr!

So it’s like the radios shows all good, connect the external meter, both the radio and the external meter is now not good, adjust the antenna, both meters shows all good, take the external meter off, suddenly the radio shows it’s not good. This is making me crazy.

Imagine the radio did not have a built in swr meter and protection for high swr, then I would trust the external one thinking it’s all good while in fact the swr would be crazy high. Why is this happening?

 

[sp5it]

First replace jumper coax.
No improvement:
Take 100Ohm resistor. Proper wattage, not wirewound.
Connect instead of antenna.
Meter should show SWR 2:1
Further from 2, bigger crap it is.
Mike

 

[SlackGirl]

First replace jumper coax.
No improvement:
Take 100Ohm resistor. Proper wattage, not wirewound.
Connect instead of antenna.
Meter should show SWR 2:1
Further from 2, bigger crap it is.
Mike

Ok so it could be as simple as that the jumper coax I have is causing this?

 

[sp5it]

Very probably.

 

[ForestRunner98]

You are in a mobile yes? I only ask because you mentioned power supply.

 

[Eldorado828]

I have to say it’s not so very easy to start with radio. First you of course need a radio, then power supply, antenna and swr meter and then study a somewhat long time to learn what the swr is, how to measure it, how important it is, what a good/bad swr is, how and why it can give false readings, what coax length you need and more.

For me this is very tiring but so far I’m stubborn enough to continue try if I can get everything to work or not.

That's one of the things about this hobby is having willingness to learn and keep trying. Trial and error. Folks who fish as a hobby don't always take home a net of fish, but they learn from it and try again.

This hobby is no different but it's a fun one. It costs too, any hobby costs and that's just part of it.

Stay at it just as you have!

 

[SlackGirl]

You are in a mobile yes? I only ask because you mentioned power supply.

Yes I am

 

[ForestRunner98]

What power supply do you have since you’re mobile? The car battery/alternator should power it just fine.

 

[144inBama]

I was honestly thinking about selling everything in a package, radio and power supply, antenna, cables and what not. And this is because it’s so complicated and unreliable when things can get totally damaged just because a radio wave that you can measure with a meter but at the same time you can’t measure it because you can get 2 different values and if I didn’t have a built in meter in the radio I would trust that meter and without knowing it a swr about 3. So from what I understand the radio would not be long lasting if this happened.

At the same time i don’t want to sell all this because I did spend a lot of time researching about power supplies and amps and antennas and god knows what. And I also think I got a really good deal on that radio based on the price I see on internet. I paid not even half what it cost but time will tell what will be. Maybe in my situation the best think would be to get a walkie talkie but that’s not what I want really.

I got my 1st CB back when Moby Dick was a minnow and it took me a loooong time to get it right. Didn't have the internet to ask questions so I wasted a lot of time and money learning the simplest of lessons. Shoot, a lot of us here have been doing this 30+ years and are still learning new things. Once you get it "close" you'll find yourself constantly working to make it better. It's a never ending journey so, good luck, hang in there and I look forward to hearing you on the waves.

 

[The DB]

Do you by chance have a magnet mount antenna?


The DB

 

[144inBama]

What type of radio is it? If equipped, are you using the "CAL" function on the radio before checking the SWR?

 

[SlackGirl]

What type of radio is it? If equipped, are you using the "CAL" function on the radio before checking the SWR?

It’s an Anytone 5555N

 

[Riverman]

Changing to a jumper of a different length often cures the problem. Just 12” difference is sufficient.

 

[144inBama]

Well....The only thing added was the external meter and jumper so, either the meter is faulty or the jumper is....or possibly both (it's 2023, nothing is impossible). The Anytone line has a pretty decent auto SWR circuit. I'd readjust the antenna using the radio. What kind of external meter are you using?

 

[AxlMyk]

The way I read this is you are using the radio for a base station, with a good 25 amp power supply, and a magnet mount antenna. Correct?