Uniden Bearcat 980ssb DOA

[unidenjim]

Hello unboxed this a few months ago started the install this week.

To make a long story short when I press talkback and key, I get nothing but noise. Is this thing even worth further troubleshooting?

Here's what I did

-bought a loaded coil antenna today from an auto retailer, and it appeared to be a returned item
-the magnet became detached from the base of the mast could see old glue, and some small non painted parts of the base where the magnet is supposed to be
-connected radio to car battery, car battery to ground
-did calibration and swr, but all was going over 1.5, up and down 6's, 3's, 2's.
-put a temporary element in with some magnet wire, snipped it back 1/8th an inch at a time calibrated checked swr some improvement
-tried the magnet mount on top of the roof, center of the trunk too
-tried grounding the antenna ground stud with jumper cables directly to bare metal on the car (antenna magnet out), still bad swr. traced the connections with multimeter.
-stretched the coax out straight still bad swr jumping all over the place
-antenna test jumping in and out of pass and fail status

-isolated the radio from the car, so i took a charged deep cycle from the garage
-connected the radio to the deep cycle, and the deep cycle to a) ground rod and other test b) fire hydrant
-rf connector to straight coax into antenna on slab of steel
-antenna even wired to the ground rod

-checked the antenna coax with multimeter for shorts there are none, no squish marks nice and round
-i tried talkback with and without antenna and it's just static
-t tried all my tests also with an HF receiver tuned to the same frequency and on +/- a few kilohertz
-nothing but static i think 'this does not modulate'
-tried different mic gains with the HF test, talkback test, nothing but static.
-radio operates like it's a spark gap transmitter i guess i could do a primitive morse code?
-tested the mic by putting it in p.a. mode with headphones on could hear myself
-i was told talkback doesn't need an antenna. talkback does not work with or without antenna.

aside from trying to glue the magnet back on the antenna, anything further i can try? i think this unit is bunk talkback doesn't operate.

bought the radio off ebay, it came in convincingly new packaging and not a sign of usage.

 

[merlin]

Your first problem to solve is from the connector at the radio to the antenna tip, something is not right and would take an antenna analyzer or VNA to find.
The talkback doesn't work for the radio shutting down because of the bad match. (or failure)
The connector can fail-first suspect.
The magnet is just to sticum to the car body, glue it back in. it gets a capacitive ground with that.
Coax center to antenna tip should be less than 2 ohms with no short to ground.
Try a dummy load on the radio. a 50 ohm 5 watt carbon resistor will work.
Your power should be over 3 watt AM mode and swr should be zero.
Monitor the radio with your HF receiver and see if the 980 modulates.
The mic could be bad.
Process of elimination to locate the problem.

 

[sloop]

My first thought when you said "bought it off ebay" was the previous owner (or some one else) put the "golden screwdriver" to it and messed it up so he sold it. Box doesn't mean anything I still have the boxes for all my radios and some are 10 years old. Get another CB'er to hook it up to their system and see if you get the same results. That should tell you if its the radio or not. Good luck.

 

[unidenjim]

i glued the antenna magnet back on with krazy glue, and now the antenna test passes with a solid "PASS" not switching between "PASS" and "FAIL" like before. also, the SWR tests give all less than 1.5, where before it was all over the place as high as 12. far away weather stations started coming in also. so gluing the magnet back on made a huge difference.

but, the talkback still gives static, and the HF receiver on the same frequency just static.

i did the resistance test from center pin to tip of element, and 0.2 ohms

maybe it's the mic but i'm skeptical since it works in PA mode.

the antenna is suspicious though since a) the magnet wasn't glued on like it's supposed to and b) it had been previously returned to the store the packaging was put back together with tape.

will try again tomorrow in a wide open parking lot. looking at digikey for these carbon resistors. maybe crimp a new uhf connector on.

i was thinking the same, just get another transmitter. not a huge deal since i plan to have another for the base anyway.

 

[unidenjim]

update. it was raining today, so i did a test inside. brought in the antenna, radio, deep cycle and a awg 4 jumper cable.

around 11:00am eastern
put the magnet antenna on the clothes dryer
ran the coax straight and flat along the floor, up to the radio on the table.
connected radio to the deep cycle battery
connected the negative terminal of the deep cycle to the house water pipe grounding strap
....
turned on the radio, did an antenna test. and it stayed on a solid PASS. first i've seen this.
did the calibration, then SWR and got solid 1.0 on both channels 1 and 40.
turned on the HF receiver and CB to channel 1.
turned talk-back on, and i could hear myself on both units! modulation works.

played around with it for about 20 minutes
decided enough is enough will try later.
about half an hour later, turn radio back on. none of the equipment moved an inch, and now i am getting really bad SWR, and the antenna test switching between pass and fail, swr graph unstable up and down from 1 to 12. managed to stabilize the swr again to about 1.4, but no modulation again just static.

ever see anything like this? i'm very confused and upset. thought i had this thing solved.

 

[slowmover]

Antenna is the problem. Until you can try another.

 

[krokus]

Why are you connecting the battery to the water pipe? That makes no sense to me.

 

[unidenjim]

Why are you connecting the battery to the water pipe? That makes no sense to me.

my guess is that it does something similar as the battery being connected to the engine block for ground. since the battery is indoors and i do not have an engine block in my kitchen to use as ground, i decided to use the cold water pipe as such. this configuration is the only time the radio worked. the user manual says "negative ground" system and illustrates the battery negative going to ground.

does this make sense or am i doing it wrong?

 

[unidenjim]

Antenna is the problem. Until you can try another.

i think so. it was in a previously opened package. curbside pickup.

 

[WA0CBW]

The "negative" radio lead is commonly called the "ground" lead and also means the common connection of all negative leads (the vehicle chassis). In this usage it does not mean earth ground.
BB

 

[k8krh]

First off, spend a few bucks and get a new antenna,not a cheap rip off antenna, also take the radio box it up, get the address of UNIDEN WEB PAGE, and send it to TEXAS, they charge $45 dollars to fix , it will be back within a few weeks.
I did with my UNIDEN, it would not transmit, they replaced few parts, and it works super, if they cannot fix it, they will send a refurbished radio to you.
So while your radio is getting fixed, buy a good antenna ,trash that junk. Lesson learned...do not but radio's <cb> off e-bay.

While you are waiting for your radio to come back, get a feeling on talking to another operator, go to the webpage called HAMSPHERE 3.0 download it, and follow the instructions, and you can talk worldwide..it is free for 7-10 days.
CEF 795/CHNL 36 USB

 

[krokus]

my guess is that it does something similar as the battery being connected to the engine block for ground. since the battery is indoors and i do not have an engine block in my kitchen to use as ground, i decided to use the cold water pipe as such. this configuration is the only time the radio worked. the user manual says "negative ground" system and illustrates the battery negative going to ground.

does this make sense or am i doing it wrong?

You do not need to connect to the water pipe with your power supply. If anything, that could be messing up your signals, making for a limited Faraday Cage.

The negative ground, when dealing with vehicles, means that the body is connected to the negative side of the battery. That is listed in the specs for gear, in case the user has a vehicle with a positive ground. (Which is very rare.)

 

[jhooten]

Negative or positive ground refers to which side of the vehicle battery is connected to the vehicle chassis. The instruction book for the radio telling you it is for a negative ground is so you can take the proper precautions if installing it in a positive ground vehicle. You don't want the chassis of a positive ground vehicle to touch the case of a negative ground radio or to connect the radio's black wire to the chassis.

 

[slowmover]

You do not need to connect to the water pipe with your power supply. If anything, that could be messing up your signals, making for a limited Faraday Cage.

The negative ground, when dealing with vehicles, means that the body is connected to the negative side of the battery. That is listed in the specs for gear, in case the user has a vehicle with a positive ground. (Which is very rare.)

I may have missed where he said he had a power supply.
My impression is a car battery carried into the house.
— In which case just run lines to POS/NEG on car battery (only) as it’s a test.

 

[krokus]

I may have missed where he said he had a power supply.
My impression is a car battery carried into the house.
— In which case just run lines to POS/NEG on car battery (only) as it’s a test.

The battery is supplying power.

 

[unidenjim]

update stuck antenna on top of a parked school bus and tested. still doing the same as being on the washer. swr floating between 1.2 and 1.5 radio almost working but cuts out to static . waiting four days now on replacement antenna.

 

[WA0CBW]

SWR shouldn't be jumping around or the radio cutting in/out. Double check the coax/connector for intermittent connections.
BB

 

[slowmover]

As with antenna, swap out coax.

 

[unidenjim]

to everyone who suggested it was the antenna they're right. retailer sold bad antenna. all tests now consistently pass will try the HF receiver when i get home. no more meters swinging all over the place except when i ptt

 

[slowmover]

Owning a known good radio to swap out (the backup) tells us right away it ain’t the radio now installed,