MTR2000 PA repair

[jstigler]

Any thoughts on a replacement transistor for the 33P68's used in the UHF 403-470 boards. We have several of these in Ham service and a couple had some PA issues. I know it is a depot exchange repair at Motorola but maybe out of our budget. Any thoughts here!
Johnny S.

[n7maq]

Any thoughts on a replacement transistor for the 33P68's used in the UHF 403-470 boards. We have several of these in Ham service and a couple had some PA issues. I know it is a depot exchange repair at Motorola but maybe out of our budget. Any thoughts here!
Johnny S.

There is a service manual for the MTR3000, I don't know how close the PA's are but I was going to do some checking. You should be able to download it of of MOL, or P25.CA



Jim

[Astro Spectra]

Some of the China-based resellers will sell small quantities, see for example:

http://www.chipsmall.com/public/goodspi ... Id=1112400

Be careful as sometimes parts are removed from scrap equipment. These houses are like brokers of surplus, over runs, inventory dumps, and other resellers. But if you're desperate it might be worth a try. They do deal with individuals, see their contact page.

I assume you've tried the obvious answer of sourcing the transistors from Motorola (I'd go via Jeff, batboard username escomm)?

[DarkHelmet]

Sorry for the old bump, but this is a good point I've not seen made anywhere else.

The amplifier "pallet" is the same between the MTR2000 and the Quantar UHF Generation 1. Pickup a broken one and desolder the transistors from one and put them in the other. The UHF R1-R3 will work for the entire UHF band. You can most likely swap the pallet if you want to.

I have a dead pallet and would be willing to pull a known good transistor off the good side of it if you still need it.

Couple pictures of the Quantar Gen 1 PA
http://wiki.w9cr.net/images/0/0c/04_UHF ... Gen_PA.jpg
http://wiki.w9cr.net/images/7/7e/05_UHF ... Gen_PA.jpg