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Justlou
New member
Username: Justlou
Post Number: 1
Registered: 3-2005
| | Posted on Tuesday, March 15, 2005 - 10:38 pm: | 
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I have an older version 88 that has a weird problem with the frequency counter. When the radio is first turned on, the counter blinks the correct frequency, then blinks another frequency. It starts at 0 MHz, and counts up to the correct frequency. The radio operates normally while this is going on. This goes on for about 2 minutes until the counter reaches the correct frequency, and then stops. It's not a temperature issue. The radio is used indoors. Any ideas??? |
2600
Intermediate Member
Username: 2600
Post Number: 497
Registered: 7-2002
| | Posted on Friday, March 18, 2005 - 11:46 pm: |
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There are a couple of voltage regulator issues that come up in that counter. Especially if it has a lot of 'miles' on it. The temperature inside the metal shield box containing the counter is higher than the surroundings.
It is a Galaxy, so checking for marginal solder connections on the counter board inside the metal shield box is a good (cheap) place to look first. If flexing the wires to the counter module cause any change in the frequency display, that's a clue something is not nailed down tightly enough.
Most of the voltage-regulator problems will behave the opposite way: works when cold, then the display goes psycho or dark after warming up.
I suggest flexing the connections to/from the two connectors on the counter module. It's not uncommon for the pins that they engage to develop a crack around the solder holding them to the pc board.
There are a couple of internal adjustments in that counter that can affect the display if they are not peaked right. Not sure I have seen written instructions for those, anywhere. If one or the other of those is on the "hair edge" of a proper tuned peak, the display can become strangely sensitive to small temperature changes.
Trust me, the temperature inside the counter shield box rises steadily for some time after you turn it on.
73
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Justlou
New member
Username: Justlou
Post Number: 2
Registered: 3-2005
| | Posted on Saturday, March 19, 2005 - 7:39 am: |
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Someone suggested that a cap might be bad on the board. I don't think it's a temperature issue since if I leave the radio on and just shut the counter off for more than a minute, when I turn the counter back on, it again counts up from 0 to the actual frequency. |
2600
Advanced Member
Username: 2600
Post Number: 500
Registered: 7-2002
| | Posted on Saturday, March 19, 2005 - 3:59 pm: |
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That is a weird one.
Covering the things we see the most often is always the safest advice to offer first.
Even with a diagram, 'scope, and somebody who can use it, it will be an uphill struggle to troubleshoot. In light of the short 'window' you have to poke an instrument inside and make a reading. By the time you look at the diagram, and decide where to poke the 'scope probe next, it's working again. After it settles down and goes back to a steady reading, there is no problem to observe. No fault to troubleshoot. Until the next 'window' after turning it back on.
Can't remember the last time I saw a "cap" go bad on that particular board.
Most often, the 3-Volt zener diode, next the 7808T regulator, next would come either of the two crystals and the HD10551 prescaler chip. The big, fat TC5032 almost never goes bad.
Nothing in there is "fail-proof", but if you have one of those one-in-a-thousand breakdowns, the statistical approach just won't help.
I'll guess that the guy who said "a cap" had no idea which ONE? I'm sure he meant well....
73
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Justlou
New member
Username: Justlou
Post Number: 3
Registered: 3-2005
| | Posted on Sunday, March 20, 2005 - 11:41 am: |
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I guess I'll just live with it for now. I just won't look at the freq counter when I first turn the radio on, until it reaches the correct freq. Then I won't even notice the problem. ;)
73 |
2600
Advanced Member
Username: 2600
Post Number: 510
Registered: 7-2002
| | Posted on Tuesday, March 22, 2005 - 1:09 am: |
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Well, in terms of just, plain cost effectiveness, that has to be the smartest strategy by far.
And if it really breaks later, that would be a reason to fix it.
73
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Justlou
New member
Username: Justlou
Post Number: 5
Registered: 3-2005
| | Posted on Thursday, March 24, 2005 - 4:42 pm: |
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Galaxy recommended a repair place, but they charge $50 and hour to troubleshoot and repair. Not worth it IMO. I just picked up a 95T yesterday, so the 88 is now a backup.  |
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