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Paging Frank Cattell Yaesu FRG-8800
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September 4th 04, 03:40 PM
Timoleon
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John Crabtree wrote:
| Timoleon,
, on 9/4/04 wrote:
|
|
|Hi Frank (and anyone else reading!) ---
|
|A couple of years ago you suggested a solution for a problem I was
|having with my FRG-8800. The display locks up and starts blinking after
|about 15 minutes of use. I think the PLL is becoming unlocked, but I'm
|just guessing.
|
|Do you remember what the problem might be, and what the solution is?
|
|Thanks!
|
|Tim
|
|
| I exchanged emails with Frank on this subject a few weeks ago. He
advised me
| that the problem is with one of the slug tuned coils which drifts, and
that the
| adjustment is covered in the service manual.
|
| The adjustment to which he was referring is on page 38 of the service
manual,
| and relates to the 2nd PLL unit. After allowing the radio to warm up
for 30
| minutes, set the radio to 10.000MHz and adjust T2007 (T07 on cct
diagram) to
| give a voltage of 5.0 volts at TP2003 (TP3 on the cct diagram). Then
set the
| radio to 29.999MHz and check for 2.0 to 3.2 volts at TP2003
|
| The PLL board is on the top of the radio when you remove the cover.
Looking
| down, with the bottom of the radio in front of you, Go roughly one
third of
| the way across the board from left to right, and one third of the way
up the
| board from bottom to top, and you will be on a smaller screening box.
Inductor
| T07 is towards the lower edge of the box. TP3 is just below the lower
left
| hand corner of the box, and IIRC is marked on the PCB.
|
| Please note that I have not made this adjustment. I was looking at
the radio
| of a friend of a friend. We measured a voltage of ca 0.98 volts at
TP3 when it
| should have been 5.0 volts. Despite a huge number of tuning tools we
did not
| have one to fit the slug. We decided to postpone our efforts until
later in
| the year.
|
| HTH and 73
|
| John KC0GGH
Thanks, John, for your answer! Although the expertise required to fix
the matter seems a little daunting --- visions of my fried body on the
floor of my shack and all... How much of a chance to I have of becoming
a pork chop by attempting the fix?
I think I'll print your post out and take it to my electrician friend!
Tim
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