Batboard

I recently acquired a radius p50 radio. Everything about it seems to work except one important feature: It will not transmit. It will recieve signals perfectly well, but will not transmit. The tx light does not come on and the speaker does not mute when the ptt button is depressed. Is there any way to fix this?

One of two things, sometimes both.

One, the PTT switch is bad. They all go bad eventually anyway. Cheap, under two bucks.

Two, the 4 MHz clock crystal on the PL option board (if it has one) is bad. Cheap, under ten bucks.

If you're comfortable taking the radio apart, throw and ohmmeter across the switch contacts, if it works, then the crystal is probably bad.

Repost if you need part numbers.

Tony

Thank you for the reply. Is there any way I can test the crystal? And could you please give me part numbers for the crystal and switch? Thank you very much.

Well, if you have a frequency counter or a service monitor (everybody here does, right:)
you can count the frequency, but usually the crystal just breaks one of its legs loose from the board.

From the latest Pricebook:

XTAL ANTIRES 18PF 4000.000KH part# 4805664G34 list price $4.85/ea.

SW PTT part# 4005286S01 list price $1.50/ea.

Happy hunting!

Do I have to purchase a crystal from motorola, or can I get just any 4 MHz crystal from radio shack?

Better get the Motorola one, I don't recommend buying anything other than OEM for repair parts. Your radio though, try it if you wish.

I personally dont think I would invest any money in crystals for that thing...especially from motorola. Maybe in 1989 it would have been cost effective, but now days for the price of the crystal set+Labor it would not be worth it. Find yourself some p110's in good condition and upgrade, or the direct replacement for the P50 the SP50 (Synthesized P50) SP50 Get it? But in all honesty, fixing a p50 is like keeping an old person on life support. Sometimes you have to just let go.

True enough, two cents, but I was not referring to TX/RX crystals, I was talking about the clock crystal the PL logic IC relies upon for pretty much all radio ops. Please read the posts carefully.

I don't like P50's either, nor do I like servicing them, but if he likes the radio and can get it up and running economically, cool.

Tony

My bad Bro...i thought this guy had a P50 that wasnt transmitting and you all had told him to see if the crystals were installed, and he said no. Maybe I should smoke a little less crack.