cb setup or bearcat 980 issue?

[napster6]

this is the 4th Bearcat 980 i have gone threw with the exact same problem i know its not the radio (unless it just cant be a base) but i cant figure out the issue so ill start with the radio

Uniden Bearcat 980
it (or should i say they) powers on fine i can hear stations just fine and the meter works but i cant put out anything when i q down on the mic. the display goes to tx and the meter shows NOTHING on am or SSB (upper or lower)

this radio has been fantastic every time i used it the problem has always been sudden. the first time it happened i sat down to use it and it was dead it happened while it was OFF second time it was while i was using it but same exact problem!! 3rd and 4th time where exactly the same as the 1st. it was working perfectly well the the next day it turned into a brick


Antenna: Imax 2000
swr on external meter shows good at 1.1 :1 and i have herd very good reports (when it was working mind you) that i sound very good both from local stations and DX stations it is mounted to the side of the house about 20' off the ground on a 6' galvanized post my roof is metal and grounded to the house. both grounded and un grounded to the roof the antenna still performs very good with good swr's ( i have not yet tamped a copper bar into the ground for a separate ground) but the radio still brakes (again not shure if this is the cause).

power supply
when i first radio i was using a motorcycle battery with a 3 amp charger then the 2-4th radios (all bearcat 980's) i bought a power supply its a Pyramid PS-21KX i picked it becaus of the positive reviews and good price. i don't know alot about power supply's but i have herd no noise coming into the radio and again reports have been good about my signal being clear when it was working

the raido is connected to the imax 2000 by a 50' RG8x coaxial cable

any help you can give me would be great

 

[Dawn]

I've seem some weird ones in marine installations where a perfectly functioning radio is replaced with a newer, gee-whiz microprocessor based unit and the radio goes nuts from shutting down, locking up to all kinds of problems including turning into a brick.

First thing to try is put a cheap, pl-259 based dummy load on your radio and then see if it operates normally. If it works fine, you're halfway home. Next would be to clear the feedline. Take the dummy load up to the roof and use a barrel adapter and terminate the line on the other end. If everything is still good, the proble must lie with the antenna. It wouldn't hurt to take an ohm meter and make sure the cable has continuity on the from the shield at both ends and the center on both ends. You can get what appears to be a good match or close to it with an open shield that will change over frequency. You claim your power supply/and batteries are good, but make sure the voltage isn't sagging on tx just in case. You also hint that this is never a problem in the mobile, just the base. You also say 4 radios have done this. Highly improbable the radios are at fault unless it's a batch issue and they are all from the same production. If that's the case, you'd probably see the effect in the mobile or with a dummy load.

You may be experiencing feedline radiation and rf getting back into the radio. Everything can be fine in the installation, but many antennas that don't use radials such as half waves are notorious for line radiation. The cure can be a bunch of snap on ferrite cores around the coax before the cable enters the house and maybe even a dc filter going into the radio.

You'd have to have rf coming out in the first place for this effect to happen. RF getting back into the radio can do everything from trigger final protection circuitry to scrambling the microprocessor if things aren't shielded well and grounded well. I've never seen this at low power, but with today's radios getting cheaper and cheaper built and more reliant on micro's for everything, anything is possible

 

[napster6]

I checked the voltage of my power supply and it does have a 0.3v drop at 20 amps so I don't think that is the problem.

I did perchace a gpk for the imax 2000 so it has Raidals

If a lot of RF was getting into my RADIO wouldn't that effect my swr (witch shows as very good)?

Any more help would be greatly appreciated

 

[sloop]

Some more questions...
1. were the radios 'tweaked' and if so was it by the same person?
2. If radios were not tweaked...then it must be rf feed back from antenna. Most cb's are not protected against high swr.
3. Were you using the internal swr meter or an external? If internal get an external one.
4. It is possible to show a low swr on a shorted feed line....try the radios on a different antenna.

 

[SouthernRoller]

I'm anxious to see what you come up with, as I have been considering a 980 myself...

 

[FrankieZ28]

i have the exact same setup with the imax 2000 and it just happened to me...talking and it went dead...had radio 2 days....can hear but i can't transmit..i hooked it up to my spare handheld radio i got for $5 at a garage sale and its working great.
swr 1.1 wow!!..toooo much of a coincidence with this radio....do yourself a favour and stay away from this radio!

 

[napster6]

Just had the repaird 980 die on me again exatly the same way so im still looking for somthing to blame for the 5th time.

When i first started out i had a power supply short threw my coax to the antenna because the base of the antenna was touching somthing with 120ac but it poped my powersupply and the raido worked after that for a while on a different powersupply

Yes i moved the antenna away from the problem and ive had 100+ contacts threw skip since so idk if it ruined my antenna or my coax or if its just that the bearcat is extreemly fragile to static from storms/weather

Again any knowledge would be greatly appreciated

 

[03msc]

Just had the repaird 980 die on me again exatly the same way so im still looking for somthing to blame for the 5th time.

When i first started out i had a power supply short threw my coax to the antenna because the base of the antenna was touching somthing with 120ac but it poped my powersupply and the raido worked after that for a while on a different powersupply

Yes i moved the antenna away from the problem and ive had 100+ contacts threw skip since so idk if it ruined my antenna or my coax or if its just that the bearcat is extreemly fragile to static from storms/weather

Again any knowledge would be greatly appreciated

You say the meter shows nothing. The meter on the CB? Do you know for certain it is not transmitting? Someone monitoring the channel does not hear you key up? You are sure you aren't hitting the button to change the meter to a different setting? Sorry if those are "dumb" questions but I saw a Youtube demo video of these 880/980 radios and the Cobra 29LX and the meters have different settings and I don't remember which but one of them would show nothing when keyed (by design). Just a thought...

 

[iMONITOR]

I'm anxious to see what you come up with, as I have been considering a 980 myself...

+1

 

[Oldme]

"When i first started out i had a power supply short threw my coax to the antenna because the base of the antenna was touching somthing with 120ac but it poped my powersupply and the raido worked after that for a while on a different power supply".

I would be concerned with what happened to the antenna system when the base hit the 120ac.
The antenna or coax could either or both have a short.