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Uniden 980 not transmitting

222DBFL said:
Clean, clear audio. No drift on SSB, and was on freq out of the box. For the money what more could you ask for. They aren't a powerhouse but they do have clean audio. Just my experience with the one I have.
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This was my experience, too. With an Astatic 636 and the on-board mic gain turned up 3/4, it sounded top notch. I just didn't expect it to crap out after 6 months of softball use. It was putting out 3 watts on AM and peaked at about 9.6 in SSB mode, so it isn't like it was pushed hard or anything like that.

I've got a relatively new Bearcat 980 that does everything it is supposed to do except transmit. I need to find a good tech to replace the blown MOSFET finals on this for me. The guy I used up in Miami retired.
 
Rick330man said:
I need to find a good tech to replace the blown MOSFET finals on this for me. The guy I used up in Miami retired.
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Heck, if I wasn't on the opposite coast, I'd offer to fix it for you cheap.

Go into business doing it yourself! Link to the part in one of my earlier posts. This is all the rest of what you need, and some practice:

Amazon product ASIN B00U1SFNYE
Amazon product ASIN B00ANZRT4M
You could use a cheaper soldering iron, but this thing is a Cadillac, I abuse one every day at work and its doing fine.

If you can find one of these cheap at a swap meet, BUY IT. It will probably outlive you:
http://www.edsyn.com/product/951SX.html

807
 
I would have the final and driver switched to maybe a 1969 final and whatever drivers needed. Maybe a better voltage regulator? But again, these things cost more money. Seems the best option to keep the heat down and possible failure of the final, is a heat sink like posted earlier. I still say for the money they aren't bad radios. Just need some improvements. Add $25 to the price and use some good parts!!
 
Thanks for the tip on the vendor for the MOSFET RF finals. I just ordered from them.

807losangeles said:
Ok, the Mitsubishi RD16HHF1 RF mosfet can be had here, 2 for ten bucks:
http://www.kitsandparts.com/transistors.php

I've purchased several times from these folks and have been very pleased. I have 4 of these mosfets on hand for my 980SSB. ;)

You can probably get it for around $4.50 from RFParts, but you have their $20 or $25 minimum order to contend with.



--->There is likely a good reason these radios come from the factory only doing 3W d/k! <---

I saw somewhere on these forums where a guy added an external heat sink on the back of his 980, just by adding a longer 4/40 screw. This is an excellent idea.

If there is interest, maybe later this weekend I can post a how-to on how to test a mosfet with a DMM set to the diode-test function.

Good luck,
807
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Ha! I have one that has no TX and when I tested the mosfet it showed good. I replaced the mosfet anyways as they are cheap. Radio still had no output. It would be nice to find at least a schematic. Been looking for the service manual for it but nothing.
 
Uniden never released the service information for that radio. Now that they are discontinued probably never will.
 
I wish there was a schematic somewhere. I have 2 first gen boxes. 1 had blown rd16hhf1 mosfet and the 1725 pnp transistor. Surface mount components and double sided board with eyelets. No hell to work on. Checked and compared the good radio to the bad. Resistance and then voltage checks. Anyhow, ordered the mosfets and transistors in 10 packs. Unreal. Tried out a new mosfet and the radio started blowing fuses. Removed the good mosfet from the known good radio and tried a 2nd new mosfet in it. That radio started blowing fuses. Put the good mosfet into the bad radio and it worked. So,, I tried out 2 more mosfets. CRAP! CHINESE GARBAGE! ripped off. Tuned it to provide no more than 3 watts accross the spectrum. Then, Switched over to ssb. BLEW a 10 ohm microscopic resistor close to the mosfet and close to 2 small D shaped transistors which are possibly drivers for the mosfet. Without a schematic its a ball breaker. Micro surgery. Replaced the small 1 millionth of a watt 10 ohm resistor with a 16th of a watt 10 ohm. With a Full whistle and audio test on ssb there's nothing more than 3 to 4 watts ssb and that resistor I replaced heats right up still. In AM the resistor is cold and output is fine. In Ssb even unmodulated that resistor gets super hot. Gonna try to figure out where it connects. 10 ohms must be for biasing either a driver or the mosfet itself. I pulled that good mosfet back out and put it back into the known good radio and its working properly and surprisingly didnt blow yet so my 2nd radio has problems. Anyone have a clue or did I just confuse the heck out if yall including myself?
 
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vswr said:
I wish there was a schematic somewhere. I have 2 first gen boxes. 1 had blown rd16hhf1 mosfet and the 1725 pnp transistor. Surface mount components and double sided board with eyelets. No hell to work on. Checked and compared the good radio to the bad. Resistance and then voltage checks. Anyhow, ordered the mosfets and transistors in 10 packs. Unreal. Tried out a new mosfet and the radio started blowing fuses. Removed the good mosfet from the known good radio and tried a 2nd new mosfet in it. That radio started blowing fuses. Put the good mosfet into the bad radio and it worked. So,, I tried out 2 more mosfets. CRAP! CHINESE GARBAGE! ripped off. Tuned it to provide no more than 3 watts accross the spectrum. Then, Switched over to ssb. BLEW a 10 ohm microscopic resistor close to the mosfet and close to 2 small D shaped transistors which are possibly drivers for the mosfet. Without a schematic its a ball breaker. Micro surgery. Replaced the small 1 millionth of a watt 10 ohm resistor with a 16th of a watt 10 ohm. With a Full whistle and audio test on ssb there's nothing more than 3 to 4 watts ssb and that resistor I replaced heats right up still. In AM the resistor is cold and output is fine. In Ssb even unmodulated that resistor gets super hot. Gonna try to figure out where it connects. 10 ohms must be for biasing either a driver or the mosfet itself. I pulled that good mosfet back out and put it back into the known good radio and its working properly and surprisingly didnt blow yet so my 2nd radio has problems. Anyone have a clue or did I just confuse the heck out if yall including myself?
Click to expand...
The current final PA transistor in the 980SSB is the IRFZ24.
 
9C1Driver said:
Read all about it.
Click to expand...

We're a year past when that was written, yet the 980 SSB remains widely available. Simon's brought us some good stuff in the past, but I think this one is a miss on his part.

This rumor about the 980 SSB being discontinued has been going around since at least 2017. https://www.worldwidedx.com/threads/uniden-980-discontinued.211397/

Can anyone provide anything from Uniden that says they're going to stop making them? If production truly ended a year ago there should be some statement about it by now.
 
If they have discontinued them they must have a lot of stock, they sell them on Amazon for $152
I just called uniden customer support, but they are closed already.
Someone hit them up tuesday morning and find out.
8002971023

73
Jeff
Screenshot_20230901-145014~2.png
 
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