Help with GCR-9
 

Hi
I recently bought an old Receiver from out of an old
GCR-9 I have no info other than a circuit pasted into
the bottom plate, I have hooked it up with 1.4volt
heaters and 90v HT also there seemed to be a 4volt
Battery that didn't seem to do much on the grid of
the audio amp is that correct?
The receiver seems quite noisy is this usual for these
old receivers? I can't find anything obviously wrong
but I have little experiance of these 1.4volt tubes
Has anyone got the pinout of the connector plug
and supply voltages to it? perhaps I've missed something :(
thanks
from Ron...

In article ,
(Ron) writes:

I recently bought an old Receiver from out of an old
GCR-9 I have no info other than a circuit pasted into
the bottom plate, I have hooked it up with 1.4volt
heaters and 90v HT also there seemed to be a 4volt
Battery that didn't seem to do much on the grid of
the audio amp is that correct?

You do want that -4V of grid bias on the audio amp grid. The good old ancient
"C" battery from the 1920s seems to have made a comeback in this set :-)

The receiver seems quite noisy is this usual for these
old receivers? I can't find anything obviously wrong
but I have little experiance of these 1.4volt tubes

"Noise" would be the usual suspects -- resistors, capacitors, and of course
dirty tube sockets and pins. But those 1.4V tubes are notoriously microphonic,
and will sing out with a "ping" each time you bump the chassis or flip a
switch. Sometimes a tube will just start singing on its own, with feedback
from the speaker. Replacing tubes or swapping identical types around in the
set may help.
73, Mike K.

Oscar loves trash, but hates Spam! Delete him to reply to me.

In article ,
(Ron) writes:

I recently bought an old Receiver from out of an old
GCR-9 I have no info other than a circuit pasted into
the bottom plate, I have hooked it up with 1.4volt
heaters and 90v HT also there seemed to be a 4volt
Battery that didn't seem to do much on the grid of
the audio amp is that correct?

You do want that -4V of grid bias on the audio amp grid. The good old ancient
"C" battery from the 1920s seems to have made a comeback in this set :-)

The receiver seems quite noisy is this usual for these
old receivers? I can't find anything obviously wrong
but I have little experiance of these 1.4volt tubes

"Noise" would be the usual suspects -- resistors, capacitors, and of course
dirty tube sockets and pins. But those 1.4V tubes are notoriously microphonic,
and will sing out with a "ping" each time you bump the chassis or flip a
switch. Sometimes a tube will just start singing on its own, with feedback
from the speaker. Replacing tubes or swapping identical types around in the
set may help.
73, Mike K.

Oscar loves trash, but hates Spam! Delete him to reply to me.

Hi Thanks for that, I seem to have got the type wrong
its from a AN/GRC-9 so I'm told
I'm pretty sure I must have the volts and connections wrong
somewhere, there are two pins I'm not sure of, pin 4 seems
to be the HT feed to the Audio Amp and pin 5 the HT for the
rest of the set, I have joined them together and fed them with 90v?
The noise is just plain Hiss, background hiss on everything
I can't seem to get a nice quiet signal even though it seems
quite sensitive, yes the valves are quite mikey, I don't understand
the volume control either, why is it dual ganged? is there some
sort of AGC control involved?
from Ron...


On 28 Oct 2003 05:29:59 GMT, r (Mike Knudsen)
wrote:

In article ,
(Ron) writes:

I recently bought an old Receiver from out of an old
GCR-9 I have no info other than a circuit pasted into
the bottom plate, I have hooked it up with 1.4volt
heaters and 90v HT also there seemed to be a 4volt
Battery that didn't seem to do much on the grid of
the audio amp is that correct?

You do want that -4V of grid bias on the audio amp grid. The good old ancient
"C" battery from the 1920s seems to have made a comeback in this set :-)

The receiver seems quite noisy is this usual for these
old receivers? I can't find anything obviously wrong
but I have little experiance of these 1.4volt tubes

"Noise" would be the usual suspects -- resistors, capacitors, and of course
dirty tube sockets and pins. But those 1.4V tubes are notoriously microphonic,
and will sing out with a "ping" each time you bump the chassis or flip a
switch. Sometimes a tube will just start singing on its own, with feedback
from the speaker. Replacing tubes or swapping identical types around in the
set may help.
73, Mike K.

Oscar loves trash, but hates Spam! Delete him to reply to me.

Hi Thanks for that, I seem to have got the type wrong
its from a AN/GRC-9 so I'm told
I'm pretty sure I must have the volts and connections wrong
somewhere, there are two pins I'm not sure of, pin 4 seems
to be the HT feed to the Audio Amp and pin 5 the HT for the
rest of the set, I have joined them together and fed them with 90v?
The noise is just plain Hiss, background hiss on everything
I can't seem to get a nice quiet signal even though it seems
quite sensitive, yes the valves are quite mikey, I don't understand
the volume control either, why is it dual ganged? is there some
sort of AGC control involved?
from Ron...


On 28 Oct 2003 05:29:59 GMT, r (Mike Knudsen)
wrote:

In article ,
(Ron) writes:

I recently bought an old Receiver from out of an old
GCR-9 I have no info other than a circuit pasted into
the bottom plate, I have hooked it up with 1.4volt
heaters and 90v HT also there seemed to be a 4volt
Battery that didn't seem to do much on the grid of
the audio amp is that correct?

You do want that -4V of grid bias on the audio amp grid. The good old ancient
"C" battery from the 1920s seems to have made a comeback in this set :-)

The receiver seems quite noisy is this usual for these
old receivers? I can't find anything obviously wrong
but I have little experiance of these 1.4volt tubes

"Noise" would be the usual suspects -- resistors, capacitors, and of course
dirty tube sockets and pins. But those 1.4V tubes are notoriously microphonic,
and will sing out with a "ping" each time you bump the chassis or flip a
switch. Sometimes a tube will just start singing on its own, with feedback
from the speaker. Replacing tubes or swapping identical types around in the
set may help.
73, Mike K.

Oscar loves trash, but hates Spam! Delete him to reply to me.

OK, here are the GRC-9 receiver pinouts from the TM:

1. sidetone
2. net +105v dc
3. receiver +105v dc
4. +105v dc
5. gnd
6. receiver +1.4v dc
7. mod tube control
8. antenna
9. antenna

OK, here are the GRC-9 receiver pinouts from the TM:

1. sidetone
2. net +105v dc
3. receiver +105v dc
4. +105v dc
5. gnd
6. receiver +1.4v dc
7. mod tube control
8. antenna
9. antenna

"Ron" wrote in message
...
Hi Thanks for that, I seem to have got the type wrong
its from a AN/GRC-9 so I'm told


I think the slang for that set is the "ANGRY-9". Very nice
receiver!

Pete

I would have guessed AN/GRR-9, the hand-cranked HF radio receiver.