Spectra D37 A5 VCO unlock.

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PETNRDX
Posts: 872
Joined: Sun Nov 25, 2001 4:00 pm
What radios do you own?: Too many

Spectra D37 A5 VCO unlock.

Post by PETNRDX »

Here is my problem...
D37 A5 900 Mhz Spectra that has been in my possession for nearly 20 years.
Working fine and used a lot until about 7 years ago.
Last year or so I have only used it a little, now 900 activity is picking up a lot.
Started to get that "thump" in the speaker on mode or volume change.
So, today decided I better do the re-cap.
( I have been carefully inspecting the caps periodically, no leakage seen )
Changed all the electrolytics, very little leakage hidden under the caps when removed.
Cleaned per the usual.
Fired up the radio, Rx good, TX on DIRECT is good, but not Rpt. FAIL 001 instantly.
Opened the case, removed the RF board shield to take a look, radio worked fine for about two minutes.
VCO is around 4.3 v on RX, same on TX Direct.
VCO basically Zero ( .16 v ) when unlocked.
Freqs are all in the 902 range.
Again, this radio has worked fine for years.
Compared the voltages at all the new caps with a working "sister" radio on same freqs, and those voltages are nearly the same.
Same with OSC voltage.
Any body have an idea.
These have the resistor VCO mod ( 150 ohm )
Steve K.
Will
Posts: 6823
Joined: Tue Sep 04, 2001 4:00 pm

Re: Spectra D37 A5 VCO unlock.

Post by Will »

You did not get the damage off the RF/IF board.
PETNRDX
Posts: 872
Joined: Sun Nov 25, 2001 4:00 pm
What radios do you own?: Too many

Re: Spectra D37 A5 VCO unlock.

Post by PETNRDX »

Lets not be insulting.
I fixed the damage which was VERY minimal considering the age of my Spectras. They are 1990.
The problem was even dumberer than that...
In working on the radio, most of the time, I had the chassis oriented VCO/Rf board up, VCO towards me, RF board away.
In working on that side of the radio, I lifted the VCO board just enuf to pull the mating pins out of the RF board.
When putting the board back in, the last pin went OUTSIDE the little socket but apparently stayed in contact just enuf to work once in awhile.
On disassembling the radio again, I saw the bent pin.
Now fixed.
Steve K.
RADIOMAN2002
Posts: 1102
Joined: Thu Apr 04, 2002 4:00 pm
What radios do you own?: More than I can count

Re: Spectra D37 A5 VCO unlock.

Post by RADIOMAN2002 »

Your lucky, I have broken more than a few pins by not paying attention.
PETNRDX
Posts: 872
Joined: Sun Nov 25, 2001 4:00 pm
What radios do you own?: Too many

Re: Spectra D37 A5 VCO unlock.

Post by PETNRDX »

Yes, I am VERY lucky.
Those pins are fragile, and I know it.
I was tired and lucky I didn't ruin an otherwise good radio...
Steve K.
com501
Posts: 1088
Joined: Fri Nov 02, 2001 4:00 pm
What radios do you own?: Over 50 - All Motorola

Re: Spectra D37 A5 VCO unlock.

Post by com501 »

'bout time you got on the local 900 repeaters..... :D
PETNRDX
Posts: 872
Joined: Sun Nov 25, 2001 4:00 pm
What radios do you own?: Too many

Re: Spectra D37 A5 VCO unlock.

Post by PETNRDX »

I am on 927.35 all day.
And there is a new repeater going up VERY soon.
You and Paul need to get on there.
The Slide system is kind of noisy, but I heard from the owner that they plan to make that much better when snow allows...
Steve K.
com501
Posts: 1088
Joined: Fri Nov 02, 2001 4:00 pm
What radios do you own?: Over 50 - All Motorola

Re: Spectra D37 A5 VCO unlock.

Post by com501 »

Working on it, but I don't have a handheld, I'm more of a mobile guy. Paul rarely brings his in, I'll remind him.
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