"Eddie Haskel" wrote in message
.. .
The 7815 needs only 3 volts of headroom, so 23 volts is plenty. Any more
than that will be dissapated as heat. Your right that the traces will also
get warm but it's still safe. The other post that advised the use of
freeze
spray was a good one too. I have used both...Eddie
"Henry Kolesnik" wrote in message
...
See my previous post about finding the culprit but I had another problem
and
it was the 7815 3 term reg which I replaced with NOS and the Wavetek
came
to
life but not great. I measured the 15 volt terminal and it was 23 volts
so
I may not have much left. I have question on your method. For a
shorted

I think he was referring to a 15 volt rgeulator that has 23 volts on the
output indicating it was bad and the overvoltage caused other components to
go bad.

23 voolts on output!
later
"Ralph Mowery" wrote in message
...

"Eddie Haskel" wrote in message
.. .
The 7815 needs only 3 volts of headroom, so 23 volts is plenty. Any more
than that will be dissapated as heat. Your right that the traces will
also
get warm but it's still safe. The other post that advised the use of
freeze
spray was a good one too. I have used both...Eddie
"Henry Kolesnik" wrote in message
...
See my previous post about finding the culprit but I had another
problem
and
it was the 7815 3 term reg which I replaced with NOS and the Wavetek
came
to
life but not great. I measured the 15 volt terminal and it was 23
volts
so
I may not have much left. I have question on your method. For a
shorted

I think he was referring to a 15 volt rgeulator that has 23 volts on the
output indicating it was bad and the overvoltage caused other components
to
go bad.

"Henry Kolesnik" wrote in message
...
23 voolts on output!
later


The way I read it , the 15 volt regulator had gone bad and was passing a
much higher voltage as it was not regulating . That was giving 23 volts on
the output instead of the 15 volts it was suspose to.

When I got the 188 the 7815 output was nearly zero and I assume the shorted
tantalum caused the low voltage. After I found the bad tantalum and
replaced it the 7815 voltage was still very and the output pin to ground
mesured 12 ohms. I had a NOS Radio Shack 7815 still sealed in its package
so Iused it and that's when pin 3 went to 23 volts and that nearly made a
grown man cry because I thought I fried addtional components. The PCB was
running too hot. After getting a known good 7815 the B+ stayed at 15 volts
and the unit runs cooler and seems to function except that the dial
calibration is off. I'm trying to find a manual.
73
hank wd5jfr
"Ralph Mowery" wrote in message
...

"Henry Kolesnik" wrote in message
...
23 voolts on output!
later


The way I read it , the 15 volt regulator had gone bad and was passing a
much higher voltage as it was not regulating . That was giving 23 volts
on
the output instead of the 15 volts it was suspose to.

I found a good 7815 and installed it and except for the frequency dial being
off the thing seems to work. If I find a manual I should be able to cal it
or find out if the cal is off because of a failed componet because of being
overstressed to 23 volts when it was designed to operate at 15 volts. The
output remains flat from 0 to 4 MHz but the when the dial reads 4 MHz the
counter shows 3.5 MHz. At 1MHz on the dial the counter reads 0.570MHz and
similar readings on at audio frequencies.
hank wd5jfr
"Ralph Mowery" wrote in message
...

"Eddie Haskel" wrote in message
.. .
The 7815 needs only 3 volts of headroom, so 23 volts is plenty. Any more
than that will be dissapated as heat. Your right that the traces will
also
get warm but it's still safe. The other post that advised the use of
freeze
spray was a good one too. I have used both...Eddie
"Henry Kolesnik" wrote in message
...
See my previous post about finding the culprit but I had another
problem
and
it was the 7815 3 term reg which I replaced with NOS and the Wavetek
came
to
life but not great. I measured the 15 volt terminal and it was 23
volts
so
I may not have much left. I have question on your method. For a
shorted

I think he was referring to a 15 volt rgeulator that has 23 volts on the
output indicating it was bad and the overvoltage caused other components
to
go bad.