Need info, Micor UHF PA stage 2 transistor

[canalradio]

I need info on the stage 2 device for a Micor base PA TLE1693A. Transistor is Motorola part 48-869851, type M9851, 5W in, 12W out. Any info on this part would be helpful, it seems hard to find. I was told this pa design used non-Motorola parts from a Calif. source, possibly CTC or TRW.
Thanks

[chartofmaryland]

Welcome to the Board,

This looks like it would be best served by purchasing an entire PA from Ebay and harvesting components.

Sadly that is still what I have to do nowadays and or find preferred replacements i.e. taking a Syntor 100 watt mobile, slicing off the PA and mounting it onto an acceptable heatsink say a retired 150 watt 800 MHz VoCom PA chassis with some additional fans

Best of luck

[Astro Spectra]

There is a TLE 1693 on eBay right now.

[canalradio]

Thanks, saw that on e-bay. Bought a used board with all 3 devices. I was really interested if anyone on here had actually found current stage 2 replacement device. The output device is available as an MRF-644 or NTE-366. I have seen stage one advertised too. If I was to guess it looks like stage 2 might be replaced with MRF-641. Stage 2 and 3 use the same base and collector caps, (25.5pf), so do the MRF-641 and MFR-644 test fixtures, close anyway. I may try an MRF-641 as an experiment.






















stage I may try it for an experiment.

[canalradio]

Got my two PA's working. The board off e-bay had different devices for stage 1 and 2, while stage 3 was the same M9741, (which I found new on e-bay, RF parts, also NTE-366). The e-bay board stage one was M9738, stage two M9739. The M9739 2nd stage device I see is available from RF parts. I used the old scrap board part M9739 and an MRF-644 to replace stages 2 and 3 on one pa. With full battery (13 Volts) on the first stage drive voltage, the pa with the original M9741 output part puts out 45 Watts, the other with the MRF-944 puts out 38 Watts. It's billed as a 25 Watt pa. I hope this helps if anyone is fixing some of these.

[canalradio]

I lost my latest post update somehow. The spare board off e-bay had different parts for stages 1 and 2 while stage 3 retains the M9741. Stage one is M9738, while stage two is M9739 and is available from RF Parts. I did replace the output device M9741 with an MRF-644 and it does work.