Hi all

Getting the beast working well. Have now traced many resistors that have
gone high, and apparently I did not fatally damage (see other post) C22 at
all (range 3 still works well though tuning may be a bit out. That's for a
later check). Now there some voltages I can't get right and I'm wondering
if there are any errors in the EMER fault finding tables. For example, V10
(1st AF) had an anode voltage that was much too low and of course that was a
resistor that went high. But on replacng that I now have 60 volts on the
anode and according to the EMER chart it should be 40. I am allowing a +-
20% tolearnce but 50% is too much I feel.

Cheers

Hi, which EMER are you refering to? In my 'original' RCAF manual (
E0 35BB-5GR17-2), dated 26 JAN 55, for the GR-17 (aka AR-88LF) the
first audio (V10) is a 6SJ7 which according to the manual should have
83V on the plate, 34V on G2 and 0V on the cathode. If V10 seems a bit
hot check R39 (100 ohm) from cathode to earth. The values for the
CR-91A are the same but the CR-88 is different, 1.1V for G1, 33V for
G2 and 50V for the plate. Which resistor went high, R40 (270k) or R41
(100k)? ........... Ok, just rulled my '88 out of it's case and
checked, I have 81V on the plate. 33V on the screen and 0V on the
cathode with a line voltage of 121V. Not bad for a 65 year old piece
of gear.

Hope this helps.

BTW anyone have an spare RCAF type C5 (10D/6566) power supply they are
willing to part with?

Kevin

On Sun, 26 Jul 2009 04:28:18 +1000, "MoiInAust" wrote:

Hi all

Getting the beast working well. Have now traced many resistors that have
gone high, and apparently I did not fatally damage (see other post) C22 at
all (range 3 still works well though tuning may be a bit out. That's for a
later check). Now there some voltages I can't get right and I'm wondering
if there are any errors in the EMER fault finding tables. For example, V10
(1st AF) had an anode voltage that was much too low and of course that was a
resistor that went high. But on replacng that I now have 60 volts on the
anode and according to the EMER chart it should be 40. I am allowing a +-
20% tolearnce but 50% is too much I feel.

Cheers

Thanks very much for the response Kevin! I refer to EMER E773. This shows
V10 as a 6SJ7 as you say and with Anode (Plate) at 40V, Screen 30V and
cathode0.1V. The cathode resistor is 11% high and therefore OK, but my volts
are A 60,and S 37.

Altogether, I have V1 with screen 32% up, and grid resistance 32% high; V6
(6SG7) with cathode volts at .87 (against .5 norm) which is 74%; all
resistances at V8 (6H6) too high; and V9 with Anode resistance 503 (33%
low).


"Kevin Dooks" wrote in message
...
Hi, which EMER are you refering to? In my 'original' RCAF manual (
E0 35BB-5GR17-2), dated 26 JAN 55, for the GR-17 (aka AR-88LF) the
first audio (V10) is a 6SJ7 which according to the manual should have
83V on the plate, 34V on G2 and 0V on the cathode. If V10 seems a bit
hot check R39 (100 ohm) from cathode to earth. The values for the
CR-91A are the same but the CR-88 is different, 1.1V for G1, 33V for
G2 and 50V for the plate. Which resistor went high, R40 (270k) or R41
(100k)? ........... Ok, just rulled my '88 out of it's case and
checked, I have 81V on the plate. 33V on the screen and 0V on the
cathode with a line voltage of 121V. Not bad for a 65 year old piece
of gear.

On Sun, 26 Jul 2009 04:28:18 +1000, "MoiInAust" wrote:

Hi all

Getting the beast working well. Have now traced many resistors that have
gone high, and apparently I did not fatally damage (see other post) C22 at
all (range 3 still works well though tuning may be a bit out. That's for a
later check). Now there some voltages I can't get right and I'm wondering
if there are any errors in the EMER fault finding tables. For example, V10
(1st AF) had an anode voltage that was much too low and of course that was
a
resistor that went high. But on replacng that I now have 60 volts on the
anode and according to the EMER chart it should be 40. I am allowing a +-
20% tolearnce but 50% is too much I feel.

Cheers

On Jul 26, 4:47*am, "MoiInAust" wrote:
Thanks very much for the response Kevin! I refer to EMER E773. This shows
V10 as a 6SJ7 as you say and with Anode (Plate) at 40V, Screen 30V and
cathode0.1V. The cathode resistor is 11% high and therefore OK, but my volts
are A 60,and S 37.

Altogether, I have V1 with screen 32% up, and grid resistance 32% high; V6
(6SG7) with cathode volts at .87 (against .5 norm) which is 74%; all
resistances at V8 (6H6) too high; and V9 with Anode resistance 503 (33%
low).

"Kevin Dooks" wrote in message

...



Hi, which EMER are you refering to? *In my 'original' RCAF manual *(
E0 35BB-5GR17-2), dated 26 JAN 55, for the GR-17 (aka AR-88LF) the
first audio (V10) is a 6SJ7 which according to the manual should have
83V on the plate, 34V on G2 and *0V on the cathode. If V10 seems a bit
hot check R39 (100 ohm) from cathode to earth. The values for the
CR-91A are the same but the CR-88 is different, 1.1V for G1, 33V for
G2 and 50V for the plate. Which resistor went high, R40 (270k) or R41
(100k)? ........... Ok, just rulled my '88 out of it's case and
checked, I have 81V on the plate. 33V on the screen and 0V on the
cathode with a line voltage of 121V. Not bad for a 65 year old piece
of gear.
On Sun, 26 Jul 2009 04:28:18 +1000, "MoiInAust" wrote:

Hi all

Getting the beast working well. Have now traced many resistors that have
gone high, and apparently I did not fatally damage (see other post) C22 at
all (range 3 still works well though tuning may be a bit out. That's for a
later check). *Now there some voltages I can't get right and I'm wondering
if there are any errors in the EMER fault finding tables. For example, V10
(1st AF) had an anode voltage that was much too low and of course that was
a
resistor that went high. But on replacng that I now have 60 volts on the
anode and according to the EMER chart it should be 40. *I am allowing a +-
20% tolearnce but 50% is too much I feel.

Cheers- Hide quoted text -

- Show quoted text -

Is there any mention of the type (therefore input impedance) of the
meter used to originally record the voltages? Just a thought!

"stan" wrote in message
...
On Jul 26, 4:47 am, "MoiInAust" wrote:
Thanks very much for the response Kevin! I refer to EMER E773. This shows
V10 as a 6SJ7 as you say and with Anode (Plate) at 40V, Screen 30V and
cathode0.1V. The cathode resistor is 11% high and therefore OK, but my
volts
are A 60,and S 37.

Altogether, I have V1 with screen 32% up, and grid resistance 32% high; V6
(6SG7) with cathode volts at .87 (against .5 norm) which is 74%; all
resistances at V8 (6H6) too high; and V9 with Anode resistance 503 (33%
low).

"Kevin Dooks" wrote in message

...



Hi, which EMER are you refering to? In my 'original' RCAF manual (
E0 35BB-5GR17-2), dated 26 JAN 55, for the GR-17 (aka AR-88LF) the
first audio (V10) is a 6SJ7 which according to the manual should have
83V on the plate, 34V on G2 and 0V on the cathode. If V10 seems a bit
hot check R39 (100 ohm) from cathode to earth. The values for the
CR-91A are the same but the CR-88 is different, 1.1V for G1, 33V for
G2 and 50V for the plate. Which resistor went high, R40 (270k) or R41
(100k)? ........... Ok, just rulled my '88 out of it's case and
checked, I have 81V on the plate. 33V on the screen and 0V on the
cathode with a line voltage of 121V. Not bad for a 65 year old piece
of gear.
On Sun, 26 Jul 2009 04:28:18 +1000, "MoiInAust" wrote:

Hi all

Getting the beast working well. Have now traced many resistors that have
gone high, and apparently I did not fatally damage (see other post) C22
at
all (range 3 still works well though tuning may be a bit out. That's for
a
later check). Now there some voltages I can't get right and I'm
wondering
if there are any errors in the EMER fault finding tables. For example,
V10
(1st AF) had an anode voltage that was much too low and of course that
was
a
resistor that went high. But on replacng that I now have 60 volts on the
anode and according to the EMER chart it should be 40. I am allowing a
+-
20% tolearnce but 50% is too much I feel.

Cheers- Hide quoted text -

- Show quoted text -

Is there any mention of the type (therefore input impedance) of the
meter used to originally record the voltages? Just a thought!

Yes, but the details are in a distant workshop. From memory it was an AVO
model 40, probably 1,000 ohms per volt that was specified. I am measuring
with a very high impedance Fluke! (Probably 11 megohms). Perhaps that's it!
On the other hand the other voltages are all within limit.

"stan" wrote in message
...
On Jul 26, 4:47 am, "MoiInAust" wrote:
Thanks very much for the response Kevin! I refer to EMER E773. This shows
V10 as a 6SJ7 as you say and with Anode (Plate) at 40V, Screen 30V and
cathode0.1V. The cathode resistor is 11% high and therefore OK, but my
volts
are A 60,and S 37.

Altogether, I have V1 with screen 32% up, and grid resistance 32% high; V6
(6SG7) with cathode volts at .87 (against .5 norm) which is 74%; all
resistances at V8 (6H6) too high; and V9 with Anode resistance 503 (33%
low).

"Kevin Dooks" wrote in message

...



Hi, which EMER are you refering to? In my 'original' RCAF manual (
E0 35BB-5GR17-2), dated 26 JAN 55, for the GR-17 (aka AR-88LF) the
first audio (V10) is a 6SJ7 which according to the manual should have
83V on the plate, 34V on G2 and 0V on the cathode. If V10 seems a bit
hot check R39 (100 ohm) from cathode to earth. The values for the
CR-91A are the same but the CR-88 is different, 1.1V for G1, 33V for
G2 and 50V for the plate. Which resistor went high, R40 (270k) or R41
(100k)? ........... Ok, just rulled my '88 out of it's case and
checked, I have 81V on the plate. 33V on the screen and 0V on the
cathode with a line voltage of 121V. Not bad for a 65 year old piece
of gear.
On Sun, 26 Jul 2009 04:28:18 +1000, "MoiInAust" wrote:

Hi all

Getting the beast working well. Have now traced many resistors that have
gone high, and apparently I did not fatally damage (see other post) C22
at
all (range 3 still works well though tuning may be a bit out. That's for
a
later check). Now there some voltages I can't get right and I'm
wondering
if there are any errors in the EMER fault finding tables. For example,
V10
(1st AF) had an anode voltage that was much too low and of course that
was
a
resistor that went high. But on replacng that I now have 60 volts on the
anode and according to the EMER chart it should be 40. I am allowing a
+-
20% tolearnce but 50% is too much I feel.

Cheers- Hide quoted text -

- Show quoted text -

Is there any mention of the type (therefore input impedance) of the
meter used to originally record the voltages? Just a thought!

Further to that, Stan, I do have an el cheapo analogue meter so I will try
that. It might very well explain the 'wrong' reading on the V6 grid!

"MoiInAust" wrote in message
...

"stan" wrote in message
...
On Jul 26, 4:47 am, "MoiInAust" wrote:
Thanks very much for the response Kevin! I refer to EMER
E773. This shows
V10 as a 6SJ7 as you say and with Anode (Plate) at 40V,
Screen 30V and
cathode0.1V. The cathode resistor is 11% high and
therefore OK, but my volts
are A 60,and S 37.

Altogether, I have V1 with screen 32% up, and grid
resistance 32% high; V6
(6SG7) with cathode volts at .87 (against .5 norm) which
is 74%; all
resistances at V8 (6H6) too high; and V9 with Anode
resistance 503 (33%
low).

"Kevin Dooks" wrote in
message

...



Hi, which EMER are you refering to? In my 'original'
RCAF manual (
E0 35BB-5GR17-2), dated 26 JAN 55, for the GR-17 (aka
AR-88LF) the
first audio (V10) is a 6SJ7 which according to the
manual should have
83V on the plate, 34V on G2 and 0V on the cathode. If
V10 seems a bit
hot check R39 (100 ohm) from cathode to earth. The
values for the
CR-91A are the same but the CR-88 is different, 1.1V
for G1, 33V for
G2 and 50V for the plate. Which resistor went high, R40
(270k) or R41
(100k)? ........... Ok, just rulled my '88 out of it's
case and
checked, I have 81V on the plate. 33V on the screen and
0V on the
cathode with a line voltage of 121V. Not bad for a 65
year old piece
of gear.
On Sun, 26 Jul 2009 04:28:18 +1000, "MoiInAust"
wrote:

Hi all

Getting the beast working well. Have now traced many
resistors that have
gone high, and apparently I did not fatally damage (see
other post) C22 at
all (range 3 still works well though tuning may be a
bit out. That's for a
later check). Now there some voltages I can't get right
and I'm wondering
if there are any errors in the EMER fault finding
tables. For example, V10
(1st AF) had an anode voltage that was much too low and
of course that was
a
resistor that went high. But on replacng that I now
have 60 volts on the
anode and according to the EMER chart it should be 40.
I am allowing a +-
20% tolearnce but 50% is too much I feel.

Cheers- Hide quoted text -

- Show quoted text -

Is there any mention of the type (therefore input
impedance) of the
meter used to originally record the voltages? Just a
thought!

Yes, but the details are in a distant workshop. From
memory it was an AVO model 40, probably 1,000 ohms per
volt that was specified. I am measuring with a very high
impedance Fluke! (Probably 11 megohms). Perhaps that's
it! On the other hand the other voltages are all within
limit.
I ran into the same problem on SP-600 and other RX. The
voltage measurements at most places were done with a 1000
Ohm per volt meter and a high resistance electronic meter
will read very high on some of them.


--
Richard Knoppow
Los Angeles
WB6KBL

In article , MoiInAust wrote:

Yes, but the details are in a distant workshop. From memory it was an AVO
model 40, probably 1,000 ohms per volt that was specified. I am measuring
with a very high impedance Fluke! (Probably 11 megohms). Perhaps that's it!
On the other hand the other voltages are all within limit.

That would do it, yes. Try a Simpson 260.

With a DMM, you will read much higher than an old moving-coil meter when
reading high impedance sources (like plates... the plate resistor is a
very high value quite often).
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."