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Old March 18th 07, 02:02 PM posted to rec.radio.shortwave
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Default Does your Drake R7A Do This?

A few years ago I bought a minty Drake R7A. I sent it to Drake for a complete refurbish and they did a wonderful job. However, I always wondered about the volume output. When the volume knob is turned down all the way I still hear audio coming from my speaker or headphones. Is this typical of these units? It's not a big deal but it does make me wonder. If this is not typical, what can I do to make it work like other rigs.
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Old March 18th 07, 02:15 PM posted to rec.radio.shortwave
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Default Does your Drake R7A Do This?



John Berenyi wrote:

A few years ago I bought a minty Drake R7A. I sent it to Drake for a complete
refurbish and they did a wonderful job. However, I always wondered about the
volume output. When the volume knob is turned down all the way I still hear
audio coming from my speaker or headphones. Is this typical of these units?
It's not a big deal but it does make me wonder. If this is not typical, what
can I do to make it work like other rigs.

It is typical after a suitable replacement could no longer be found by Drake.
The same thing has apparently happened with the R8B. Proper replacements are
VERY hard to find.

Please turn your HTML off!


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Old March 18th 07, 03:35 PM posted to rec.radio.shortwave
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Default Does your Drake R7A Do This?

On Sun, 18 Mar 2007 08:02:34 -0600, "John Berenyi"
wrote in
:

When the volume knob is turned down =
all the way I still hear audio coming from my speaker or headphones. Is =
this typical of these units?



The same thing occurs with my Drake R8B.

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Old March 18th 07, 03:42 PM posted to rec.radio.shortwave
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Default Does your Drake R7A Do This?



Larry Dighera wrote:

On Sun, 18 Mar 2007 08:02:34 -0600, "John Berenyi"
wrote in
:

When the volume knob is turned down =
all the way I still hear audio coming from my speaker or headphones. Is =
this typical of these units?


The same thing occurs with my Drake R8B.


"The AF/RF gain control (5K/3K) for the R-8B is no longer available. However,
you can substitute this with the PBT/Squelch control (10K/10K), 326-0006,
available at a cost of $5.13." -- Bill Frost, Drake.

I've not tried this myself.

dxAce
Michigan
USA


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Old March 18th 07, 09:06 PM posted to rec.radio.shortwave
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Default Does your Drake R7A Do This?

On Sun, 18 Mar 2007 11:42:51 -0400, dxAce wrote
in :


Larry Dighera wrote:

On Sun, 18 Mar 2007 08:02:34 -0600, "John Berenyi"
wrote in
:

When the volume knob is turned down =
all the way I still hear audio coming from my speaker or headphones. Is =
this typical of these units?


The same thing occurs with my Drake R8B.


"The AF/RF gain control (5K/3K) for the R-8B is no longer available. However,
you can substitute this with the PBT/Squelch control (10K/10K), 326-0006,
available at a cost of $5.13." -- Bill Frost, Drake.

I've not tried this myself.

dxAce
Michigan
USA


Thanks for the information. If it came from Bill Frost, it's gospel.

However, I'm not going to open the receiver up just to check the part
number, as the low-volume audio output that remains when the volume
control is in the Min position is a non-issue for me. If I want
absolute silence, the Power switch is able to effect that quite
nicely.



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Old March 18th 07, 09:12 PM posted to rec.radio.shortwave
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Default Does your Drake R7A Do This?



Larry Dighera wrote:

On Sun, 18 Mar 2007 11:42:51 -0400, dxAce wrote
in :


Larry Dighera wrote:

On Sun, 18 Mar 2007 08:02:34 -0600, "John Berenyi"
wrote in
:

When the volume knob is turned down =
all the way I still hear audio coming from my speaker or headphones. Is =
this typical of these units?

The same thing occurs with my Drake R8B.


"The AF/RF gain control (5K/3K) for the R-8B is no longer available. However,
you can substitute this with the PBT/Squelch control (10K/10K), 326-0006,
available at a cost of $5.13." -- Bill Frost, Drake.

I've not tried this myself.


Thanks for the information. If it came from Bill Frost, it's gospel.

However, I'm not going to open the receiver up just to check the part
number, as the low-volume audio output that remains when the volume
control is in the Min position is a non-issue for me.


Bear in mind that that is Drake's part number, not necessarily the one on the pot
itself.

If I want
absolute silence, the Power switch is able to effect that quite
nicely.


At least on the R7/A there is a mute switch! In my case with the R8B and the R7 is
that the volume is very, very low in the totally counter clockwise position.

dxAce
Michigan
USA


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Old March 19th 07, 01:17 AM posted to rec.radio.shortwave
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Default Does your Drake R7A Do This?

On Sun, 18 Mar 2007 17:12:40 -0400, dxAce wrote
in :

In my case with the R8B and the R7 is
that the volume is very, very low in the totally counter clockwise position.


Exactly. And I have no issue with pressing the power switch when I
want absolute silence from the receiver.

Of course, the receiver is only truly off when it is disconnected from
a power source. I suppose that design decision was a result of the
desire to facilitate digital control via computer at all times.

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Old March 19th 07, 09:19 AM posted to rec.radio.shortwave
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Default Does your Drake R7A Do This?

Larry Dighera wrote:
On Sun, 18 Mar 2007 08:02:34 -0600, "John Berenyi"
wrote in
:


When the volume knob is turned down =
all the way I still hear audio coming from my speaker or headphones. Is =
this typical of these units?




The same thing occurs with my Drake R8B.


Mine too. It's my second R8B and the first one also did it. I'm pretty
sure it's caused by high impedance leakage around the pot. I discovered
this when I had the receiver apart for some maintenance. I removed the
connector to the volume pot and I could still hear some weak audio.
Since I use the R8B close to my bed, I installed a mute switch in the
speaker circuit so I don't hear any sound when the volume is down all
the way or up too.
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Old March 19th 07, 10:34 AM posted to rec.radio.shortwave
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Default Does your Drake R7A Do This?

On Mon, 19 Mar 2007 09:19:32 GMT, HFguy wrote in
EAsLh.8578$282.8431@trndny04:

Larry Dighera wrote:
On Sun, 18 Mar 2007 08:02:34 -0600, "John Berenyi"
wrote in
:


When the volume knob is turned down =
all the way I still hear audio coming from my speaker or headphones. Is =
this typical of these units?




The same thing occurs with my Drake R8B.


Mine too. It's my second R8B and the first one also did it. I'm pretty
sure it's caused by high impedance leakage around the pot. I discovered
this when I had the receiver apart for some maintenance. I removed the
connector to the volume pot and I could still hear some weak audio.


With the pot out of the circuit, I wonder what the signal path might
be?

I presume the 5K AF Gain pot grounds the input to U4 when it's in the
Min position. When the pot plug is removed from jack P4, the U4 amp
input floats.

Since I use the R8B close to my bed, I installed a mute switch in the
speaker circuit so I don't hear any sound when the volume is down all
the way or up too.



According to the R. L. Drake R8B Owners Manual
http://www.hamradio.no/la3tq/r8b.htm, there is an RCA jack on the
rear of the receiver labeled Mute:

MUTE - The RCA connector provides a method of
muting the receiver for use with a transmitter. Ground
center pin to mute.

Grounding the center pin of this jack fully mutes the receiver.

Just out of curiosity, why don't you just turn the receiver off when
you don't want to hear it?

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Old March 20th 07, 05:02 AM posted to rec.radio.shortwave
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Default Does your Drake R7A Do This?

Larry Dighera wrote:

On Mon, 19 Mar 2007 09:19:32 GMT, HFguy wrote in
EAsLh.8578$282.8431@trndny04:


Larry Dighera wrote:

On Sun, 18 Mar 2007 08:02:34 -0600, "John Berenyi"
wrote in
:



When the volume knob is turned down =
all the way I still hear audio coming from my speaker or headphones. Is =
this typical of these units?



The same thing occurs with my Drake R8B.


Mine too. It's my second R8B and the first one also did it. I'm pretty
sure it's caused by high impedance leakage around the pot. I discovered
this when I had the receiver apart for some maintenance. I removed the
connector to the volume pot and I could still hear some weak audio.



With the pot out of the circuit, I wonder what the signal path might
be?

I presume the 5K AF Gain pot grounds the input to U4 when it's in the
Min position. When the pot plug is removed from jack P4, the U4 amp
input floats.


Since I use the R8B close to my bed, I installed a mute switch in the
speaker circuit so I don't hear any sound when the volume is down all
the way or up too.




According to the R. L. Drake R8B Owners Manual
http://www.hamradio.no/la3tq/r8b.htm, there is an RCA jack on the
rear of the receiver labeled Mute:

MUTE - The RCA connector provides a method of
muting the receiver for use with a transmitter. Ground
center pin to mute.

Grounding the center pin of this jack fully mutes the receiver.

Just out of curiosity, why don't you just turn the receiver off when
you don't want to hear it?


I didn't spend much time studying the problem so I can't say with any
certainty how the audio may be leaking around the pot. It could have
something to do with the design of the PCB traces or maybe the wiring
lead dress. I do remember trying to make the audio silent by
substituting some resistors for the pot but it didn't have any effect. I
solved the problem by adding a mute switch (button) on the front panel
for convenience. I prefer to mute the audio because I don't like to be
cycling the receiver on and off every time I want the audio to be
completely silent. This situation usually happens when I'm in bed at
night listening to the television on low volume and the R8B is closer to
me than the TV.


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