Batboard

Hello. I have a /\/\ SP-50 10ch VHF portable. Here's the problem - when I key the radio, the PTT light blinks once and the radio unkeys. It dosen't always do this right after key-up - sometimes the radio can be keyed for 30 seconds or more before this happens. There is no low battery alarm sounded when this happens (the radio is enabled for this). Scan can be activated, but after the error occurs, no RX is possible. If I shut tehr radio off for a while, it usually "resets", and I can RX again.

The batteries are old and probably weak, and I have ordered replacements. All in all, does this sound like a battery problem, or is there something else going on inside there?

Thanks

Classic symptoms of a faulty Ni-Cad pack.

Hello:

As mentioned above " Always " make sure you have a
good battery when dealing with the SP50 Series.

If you take the battery out, and if its a original
Motorola Battery, you should see 3 big numbers
and a couple of letters.

238LU means the 23 Week of 1988 is when the battery
was made. Batteries for these SP50's last about 1 1-/2
Years, and then need replacing to keep the radio working
in a optimum enviroment.

So, if you battery is 3 ~ 4 Years Old, its almost assured the
Battery is not able to deliver the current required by the
radio when in transmitt.

In the unlikely hood you buy a New Battery, and have the
same symptoms, then chances are very high you have a
Common " Volume Control / On / Off " swich problem.

I have replaced many of these Volume Controls to restore
the proper Transmitt Output Power.

So, either one or both can cause the trouble you have
reported.

Monty

Monty and ka7wnf,

Thanks for the information. If I still have problems after I get the new pack, I'll let you know.

Go with what Montey said, but also you may have a loose battery contact (used to get them in all the time when I worked repair) but really we can't tell much til you get a new batt and see how that goes.

238LU means the 23 Week of 1988 is when the battery
was made

Actually 238 would be the 38th week of 2002.
The first digit is the last digit of the year.
The second and third digits are the week of the year.

You have to get up pretty early to catch a trip up by Monty. It is pretty rare.

And of course .. you did clean the battery contacts didn't you? (both in the radio and on the battery)

Just an eraser off of a pencil is all it takes ...

Ted...

Hello again,
I have tried several batteries, and nothing makes the radio work as it's supposed to. I had a friend check the volume knob, and he coulden't find any problems with it. It still unkeys, blinks at me, and loses RX sporadically. Any other thoughts?

I have tried several batteries

With all due respects, I have seen this
happen with " many " batteries !

In order to " Rule Out " other possibilities, U
really should try a " Brand New Battery "

If you have a Brand New freshly charged Battery,
and the Tx lamp still blinks, chances are pretty
high you may have a defective On/Off volume
switch.

If you do not have a Brand New battery, you
could take your radio to a friend that has a
Current / Voltage Regulated Power Supply and
see how much current its consumming.

Monty

I would make sure that your contacts are not broken I just recently had one of our radios do exactly what you are saying yours does. It appeared at first glance to be good but after taking a closer look I found the contact to be broken near the solder pad. The radio drove us nuts because sometimes it worked and sometimes it didn't, but then it worked again and then it didn't.....

How do I get into the radio?

If I had a dollar for every SP50 I've seen with a rubber band holding the battery on.

Reminds me of the days of the Motorola DPC550/650 or Ericsson DF388 cell phones, had to put a piece of folded cardboard to keep the battery from moving.

Well, I got rid of the sp-50. I wasn't all that happy with it anyway...I'll stick with my trusty ht-1000! Thanks for the help everyone!

Hello:

Well ?

Looks like I got the radio. Once fixed, I will make a
post about what problem was found.

If anyone wants it after it gets fixed, let me
know...

Monty