Why does my Bearcat 980s built in SWR meter only work if I have an external meter hooked up?

[highspeed556]

Why is it that if I just have my antenna connected directly to my radio, my radios SWR meter will always read 1.0 on all channels? Yet if I hook my external meter up to the radio, then the radios built in meter reads pretty similar readings to what my external meter reads (1.05 on ch 1 and 1.5 on ch 40)?

I'm really confused as to why I have to hook an external meter to the radio before the built in meter works? What's going on here?

I'm using a Uniden Bearcat 980 SSB with a Wilson 500 mag mount on the center of my roof (Ford Explorer).

 

[space cowboy]

unless your match is very different with the meter inline, it sounds like your radio meter is working fine and your match is good. the variation you're seeing with the external meter is probably just caused by the meter/jumper being inline.

 

[highspeed556]

But...should my radio's SWR meter not be able to test my SWR without having an external meter hooked up? If the external meter isn't hooked up, the radio will always just read 1.0 on all channels. I know my 4.5' antenna isn't tuned PERFECT across the entire band.

 

[The War Wagon]

That is weird, because my 980's internal SWR reads 1.5 on ch.40, down to 1.06 on ch.1, so I know it's working. That's a head-scratcher...

 

[midnight special]

not to upset any one please but i have seen a lot of wilson 500 magmounts not much better than a dummy load,,,, does it receive good how far out can you get to? hard mount with a better antenna has always been the rule,,

 

[222DBFL]

That is a bit weird. Readings should be the same or close to it. Maybe an impedance mismatch. This is when an antenna analyzer becomes handy I'll say that much!! At least you could check for an impedance imbalance. There is an adjustment pot in the radio for the swr reading, only other thing I can think of is to calibrate the radio to meet the external meter. Definitely a head scratcher this early in the AM. Hope you get it resolved. Keep us updated on what you find out.

 

[highspeed556]

not to upset any one please but i have seen a lot of wilson 500 magmounts not much better than a dummy load,,,, does it receive good how far out can you get to? hard mount with a better antenna has always been the rule,,

I've talked t folks the next county over. I even talked skip on this setup parked up on a high hill.

However at highway speeds yesterday I noticed I could only really hear or talk to truckers within about a mile or two.

 

[DainBramage]

... I know my 4.5' antenna isn't tuned PERFECT across the entire band.

a 1.0:1 VSWR is not a "perfect" antenna, a 50 om dummy load will do that and it is far from even being an antenna.

read post #2 again

 

[M0GVZ]

unless your match is very different with the meter inline, it sounds like your radio meter is working fine and your match is good. the variation you're seeing with the external meter is probably just caused by the meter/jumper being inline.

And is doing a good job of demonstrating that it is the coax which is your antenna ground and not the metal your mount is on.

But...should my radio's SWR meter not be able to test my SWR without having an external meter hooked up? If the external meter isn't hooked up, the radio will always just read 1.0 on all channels. I know my 4.5' antenna isn't tuned PERFECT across the entire band.

Its quite possible. When you have a lossy antenna and/or installation, the SWR will read flat over a far wider bandwidth. The fact that when you put the external SWR meter in line the SWR changes is proof that your antenna installation is poor and lossy. If the installation was good then the SWR wouldn't change no matter how much coax you used or how many meters you put in line.

Being generous it could be you've a dodgy connection from the coax braid to the magmount base but ultimately your problems and what you're seeing are caused by how you're mounting the antenna and what additional work on grounding you've not done. Magmounts are, have and always will be piss poor methods of mounting an antenna and getting a good ground. They should be used only for temporary short term use such as on hire cars, not for long term use.

The evidence is all there for you to see, flat low SWR over far more bandwidth than it should be, SWR altering when you change the length of the coax proving the coax and not the car body is being used for ground, the piss poor antenna range - with a hard mounted antenna I can do 30 miles mobile to mobile with 4W.

As an aside, the fact you can work DX proves nought. When conditions are good you can work DX with a dummy load as many hams have done by accident. My record for distance on low power is 7500 miles with 1 watt SSB.

 

[beachbreak]

I have the same radio and same issue. I know the radio SWR works because I built a 1/2 wave dipole and got high readings at first until I trimmed the elements a bit at a time (SWR reading kept coming down). Now it reads 1.0 across the band, CH1 - CH40. I think the meter isn't very sensitive, and the 1.0 is really 1.2 - 1.4 or something but it shows as 1.0. When I hooked up external meter it was a bit higher. My Wilson 1000 on my truck reads 1.0 also but a K30 I had read 1.8 or so. So it works, just not calibrated exactly.

 

[222DBFL]

It needs at least a couple watts of carrier to get the swr meter to read correctly as well so I've heard. My DK is set at 3 watts and my internal meter reads fine. Could be a fluke or you have your dead key set too low, like below 2 watts.