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FS: TRA931P Frequency Memmory Board

 

Hi,
?
I have for sale the TRA931P Frequency Memmory Board.
50$ plus shipping
?
Pls contact me if interested.
?
?
73s, ILAN 4X6MU
?
?
Re: RA1778 Maintenance Manual

 

开云体育

Hi Richard,

I have just restored a 1779 and I'm also looking for a copy of part 2 but my previous request resulted in stunning silence....
You can do most of what you need to do with the 1771/2 manual until you get to the logic boards. If you have another working one, you could at least do some "comparison" troubleshooting.

By the way, one thing that makes these a fabulous receiver for shortwave DX is that the sideband filters are 6Khz instead of the usual 3. I was tuning around the AM shortwave bands the other day, and using exalted carrier really works well with these receivers.

Cheers,
Peter - VK2AN

From: [email protected] <[email protected]> on behalf of Richard Sellers via groups.io <r.sellers@...>
Sent: Friday, 6 December 2024 3:45 AM
To: [email protected] <[email protected]>
Subject: [RacalRadio] RA1778 Maintenance Manual
?
Good Afternonn all
?
RA1778
?
A friend has let me? have 3 x RA1778. One unit worked straight out of the box - just needed a new memory batt and some switch cleaner. I am v impressed with the performance - it's nice to use and performance is much better than expected - up there with my newer receivers.
Only thing I would like is to have the option for manual IF gain with agc but that should't be too difficult?
The second unit is basically working just needs some tlc but the 3rd one has a genuine fault - poss synth/vco fault but I only have part 1 of the manual and no drawings!
I have been looking for part 2 on and off since 2022 but now it's urgent, so can anyone help?
Kind regards
Richard
G3VDE
Re: RA6790 Filter Selection

 

My radio has seven filters the first two being LSB and USB. It is badged on the front as an R-2174(P). No ISB option and the A4 card is not jumpered for it.

Tom
W3TA

On Thursday, December 5, 2024 at 11:45:36 AM EST, Dan Rae via groups.io <danrae@...> wrote:


On 12/5/2024 7:10 AM, thoyer via groups.io wrote:
Probably a silly question, but I'm new to this radio......

Filters are selected via the BW1 thru BW5 buttons. My radio has seven filters - how are the additional filters selected?

Tom, normally FL1 has a symmetrical 3.24 kHz wide filter fitted that is used for both sidebands with some clever changing of the LO and BFO frequencies. You would usually only find separate USB and LSB filters if the radio has the ISB option.? It will only allow 5 symmetric filters for use in other modes than ssb, so there will be a vacant slot in there somewhere if there is no ISB card.?

BITE failure 33 is down to the filter in slot 3.? The logic for filter selection is quite easy to follow with a DVM, it's possible it is not being switched in or indeed faulty.

73 - Dan

ac6ao
Re: RA-6790 Internal RF Connectors

 

Thanks Dan

On Thursday, December 5, 2024 at 11:30:11 AM EST, Dan Rae via groups.io <danrae@...> wrote:


On 12/5/2024 8:16 AM, thoyer via groups.io wrote:
Are the internal RF board to board connectors MCX series? I need to make a couple cables.
SMB
Re: RA1778 Maintenance Manual

 

On 12/5/2024 8:45 AM, Richard Sellers via groups.io wrote:
Only thing I would like is to have the option for manual IF gain with agc but that should't be too difficult?
You would have to diode OR the feed(s) from the AGC source to the IF board or boards if you have ISB.? Could all be done at the switch I reckon.? But you may need to see Chapter 20 :^(

Can't help with Vol 2 I'm afraid. Can't scan my paper...? There's a really good copy of Vol1 on line, best I can remember seeing of any scans but that stops at Chap 16.

73 - Dan

ac6ao / g3ncr
Re: RA6790 Filter Selection

 

开云体育

On 12/5/2024 7:10 AM, thoyer via groups.io wrote:
Probably a silly question, but I'm new to this radio......

Filters are selected via the BW1 thru BW5 buttons. My radio has seven filters - how are the additional filters selected?

Tom, normally FL1 has a symmetrical 3.24 kHz wide filter fitted that is used for both sidebands with some clever changing of the LO and BFO frequencies. You would usually only find separate USB and LSB filters if the radio has the ISB option.? It will only allow 5 symmetric filters for use in other modes than ssb, so there will be a vacant slot in there somewhere if there is no ISB card.?

BITE failure 33 is down to the filter in slot 3.? The logic for filter selection is quite easy to follow with a DVM, it's possible it is not being switched in or indeed faulty.

73 - Dan

ac6ao
RA1778 Maintenance Manual

 

Good Afternonn all
?
RA1778
?
A friend has let me? have 3 x RA1778. One unit worked straight out of the box - just needed a new memory batt and some switch cleaner. I am v impressed with the performance - it's nice to use and performance is much better than expected - up there with my newer receivers.
Only thing I would like is to have the option for manual IF gain with agc but that should't be too difficult?
The second unit is basically working just needs some tlc but the 3rd one has a genuine fault - poss synth/vco fault but I only have part 1 of the manual and no drawings!
I have been looking for part 2 on and off since 2022 but now it's urgent, so can anyone help?
Kind regards
Richard
G3VDE
Re: RA-6790 Internal RF Connectors

 

开云体育

On 12/5/2024 8:16 AM, thoyer via groups.io wrote:
Are the internal RF board to board connectors MCX series? I need to make a couple cables.
SMB
RA-6790 Internal RF Connectors

 

Are the internal RF board to board connectors MCX series? I need to make a couple cables.

Tom
W3TA
Re: RA6790 Filter Selection

 

I think I answered my own question upon further reading of the manual. The first two slots are the LSB and USB filters selected by their respective buttons. That leaves the other five slots for BW1-BW5.

Working through this as BITE gets hung up on slot 3 - error 33. I changed the filter with another to see if it followed the filter but it doesn't, error stays on slot 3. Looks like it may be a digital issue. Slot 3 does not get selected...... Doing some signal tracing with the scope.

Tom
W3TA

On Thursday, December 5, 2024 at 10:10:56 AM EST, thoyer via groups.io <thoyer1@...> wrote:


Probably a silly question, but I'm new to this radio......

Filters are selected via the BW1 thru BW5 buttons. My radio has seven filters - how are the additional filters selected?

Tom
W3TA
RA6790 Filter Selection

 

Probably a silly question, but I'm new to this radio......

Filters are selected via the BW1 thru BW5 buttons. My radio has seven filters - how are the additional filters selected?

Tom
W3TA
Re: Racal RA-6790GM/R2174 New to Me

 

It is possible to buy LEDs with light diffusers that can fit behind LCD displays.? It's kind of hit-or-miss with the sizes though. Adafruit has a few different ones.

Like this:?

They are thicker than an EL panel and there isn't always room.? If you have the space, doing it with LEDs is definitely the way to go.

On 11/30/2024 9:31 PM, Peter E via groups.io wrote:
It may be possible but it makes it a pretty complex alternative to some simple LED's installed in place of the bulbs.
What would be really nice would be to remove the silver backing on the existing LCD's and replace that with EL panels?

Maybe a project for someone more adventurous than me....
--------------------------------------------------------------------------------
*From:* [email protected] <[email protected]> on behalf of Peter Gottlieb via groups.io <hpnpilot@...>
*Sent:* Sunday, 1 December 2024 1:28 PM
*To:* [email protected] <[email protected]>
*Subject:* Re: [RacalRadio] Racal RA-6790GM/R2174 New to Me
EL backlighting is used in plenty of sensitive transceivers. Examples include
the Harris RF-350K and Tadiran PRC-2200.


On 11/30/2024 9:25 PM, Peter E via groups.io wrote:
Probably not, but I would think even 400Hz at high voltage would generate a
fair few harmonics right inside a sensitive receiver.
--------------------------------------------------------------------------------
*From:* [email protected] <[email protected]> on behalf of Peter
Gottlieb via groups.io <hpnpilot@...>
*Sent:* Sunday, 1 December 2024 1:19 PM
*To:* [email protected] <[email protected]>
*Subject:* Re: [RacalRadio] Racal RA-6790GM/R2174 New to Me
Are the "string" wires different from regular electroluminscent panels?? Those
run at about 120 VAC 400 Hz which is pretty easy to create without much EMI.


On 11/30/2024 9:15 PM, Peter E via groups.io wrote:
Hi Dan,

I just looked up some info on electroluminescent wire. It needs to be driven
with high frequency AC at a fairly high voltage. Not something you would want
anywhere near a sensitive receiver I would think.

Cheers,
Peter
--------------------------------------------------------------------------------
*From:* [email protected] <[email protected]> on behalf of Dan Rae via
groups.io <danrae@...>
*Sent:* Sunday, 1 December 2024 9:37 AM
*To:* [email protected] <[email protected]>
*Subject:* Re: [RacalRadio] Racal RA-6790GM/R2174 New to Me
On 11/30/2024 1:27 PM, Peter E via groups.io wrote:
Hi Dan,
Absolutely correct - I actually meant to say NiMh (must be getting old).
And of course I did mean /less/ prone to leakage :^) Even older.
I like your led lighting solution. I also wonder if it is possible to use
that electroluminescent "string" that is available in various places? That
would give really even illumination
Two things there, first there is not a lot of height between the existing
board and the front panel, so not a lot of room for those strips.? Secondly
you need the small surface mount LEDs that shine sideways to light the LCDs.
The original LED lighting on the GM needed a re-worked acrylic piece to
accommodate the only LEDs that were available at the time.

I've done a few like that, the only advice I'd give would be to buy some extra
LEDs, since they have a habit of jumping off the board never to be seen again.

73 - Dan
Re: Racal RA-6790GM/R2174 New to Me

 

开云体育

It may be possible but it makes it a pretty complex alternative to some simple LED's installed in place of the bulbs.
What would be really nice would be to remove the silver backing on the existing LCD's and replace that with EL panels?

Maybe a project for someone more adventurous than me....

From: [email protected] <[email protected]> on behalf of Peter Gottlieb via groups.io <hpnpilot@...>
Sent: Sunday, 1 December 2024 1:28 PM
To: [email protected] <[email protected]>
Subject: Re: [RacalRadio] Racal RA-6790GM/R2174 New to Me
?
EL backlighting is used in plenty of sensitive transceivers. Examples include
the Harris RF-350K and Tadiran PRC-2200.


On 11/30/2024 9:25 PM, Peter E via groups.io wrote:
> Probably not, but I would think even 400Hz at high voltage would generate a
> fair few harmonics right inside a sensitive receiver.
> --------------------------------------------------------------------------------
> *From:* [email protected] <[email protected]> on behalf of Peter
> Gottlieb via groups.io <hpnpilot@...>
> *Sent:* Sunday, 1 December 2024 1:19 PM
> *To:* [email protected] <[email protected]>
> *Subject:* Re: [RacalRadio] Racal RA-6790GM/R2174 New to Me
> Are the "string" wires different from regular electroluminscent panels?? Those
> run at about 120 VAC 400 Hz which is pretty easy to create without much EMI.
>
>
> On 11/30/2024 9:15 PM, Peter E via groups.io wrote:
> > Hi Dan,
> >
> > I just looked up some info on electroluminescent wire. It needs to be driven
> > with high frequency AC at a fairly high voltage. Not something you would want
> > anywhere near a sensitive receiver I would think.
> >
> > Cheers,
> > Peter
> > --------------------------------------------------------------------------------
> > *From:* [email protected] <[email protected]> on behalf of Dan Rae via
> > groups.io <danrae@...>
> > *Sent:* Sunday, 1 December 2024 9:37 AM
> > *To:* [email protected] <[email protected]>
> > *Subject:* Re: [RacalRadio] Racal RA-6790GM/R2174 New to Me
> > On 11/30/2024 1:27 PM, Peter E via groups.io wrote:
> >> Hi Dan,
> >> Absolutely correct - I actually meant to say NiMh (must be getting old).
> > And of course I did mean /less/ prone to leakage :^) Even older.
> >> I like your led lighting solution. I also wonder if it is possible to use
> >> that electroluminescent "string" that is available in various places? That
> >> would give really even illumination
> >
> > Two things there, first there is not a lot of height between the existing
> > board and the front panel, so not a lot of room for those strips.? Secondly
> > you need the small surface mount LEDs that shine sideways to light the LCDs.
> > The original LED lighting on the GM needed a re-worked acrylic piece to
> > accommodate the only LEDs that were available at the time.
> >
> > I've done a few like that, the only advice I'd give would be to buy some extra
> > LEDs, since they have a habit of jumping off the board never to be seen again.
> >
> > 73 - Dan
> >
> >
>
>
>
>
>
>
>






Re: Racal RA-6790GM/R2174 New to Me

 

EL backlighting is used in plenty of sensitive transceivers. Examples include the Harris RF-350K and Tadiran PRC-2200.

On 11/30/2024 9:25 PM, Peter E via groups.io wrote:
Probably not, but I would think even 400Hz at high voltage would generate a fair few harmonics right inside a sensitive receiver.
--------------------------------------------------------------------------------
*From:* [email protected] <[email protected]> on behalf of Peter Gottlieb via groups.io <hpnpilot@...>
*Sent:* Sunday, 1 December 2024 1:19 PM
*To:* [email protected] <[email protected]>
*Subject:* Re: [RacalRadio] Racal RA-6790GM/R2174 New to Me
Are the "string" wires different from regular electroluminscent panels?? Those
run at about 120 VAC 400 Hz which is pretty easy to create without much EMI.


On 11/30/2024 9:15 PM, Peter E via groups.io wrote:
Hi Dan,

I just looked up some info on electroluminescent wire. It needs to be driven
with high frequency AC at a fairly high voltage. Not something you would want
anywhere near a sensitive receiver I would think.

Cheers,
Peter
--------------------------------------------------------------------------------
*From:* [email protected] <[email protected]> on behalf of Dan Rae via
groups.io <danrae@...>
*Sent:* Sunday, 1 December 2024 9:37 AM
*To:* [email protected] <[email protected]>
*Subject:* Re: [RacalRadio] Racal RA-6790GM/R2174 New to Me
On 11/30/2024 1:27 PM, Peter E via groups.io wrote:
Hi Dan,
Absolutely correct - I actually meant to say NiMh (must be getting old).
And of course I did mean /less/ prone to leakage :^) Even older.
I like your led lighting solution. I also wonder if it is possible to use
that electroluminescent "string" that is available in various places? That
would give really even illumination
Two things there, first there is not a lot of height between the existing
board and the front panel, so not a lot of room for those strips.? Secondly
you need the small surface mount LEDs that shine sideways to light the LCDs.
The original LED lighting on the GM needed a re-worked acrylic piece to
accommodate the only LEDs that were available at the time.

I've done a few like that, the only advice I'd give would be to buy some extra
LEDs, since they have a habit of jumping off the board never to be seen again.

73 - Dan
Re: Racal RA-6790GM/R2174 New to Me

 

开云体育

Probably not, but I would think even 400Hz at high voltage would generate a fair few harmonics right inside a sensitive receiver.

From: [email protected] <[email protected]> on behalf of Peter Gottlieb via groups.io <hpnpilot@...>
Sent: Sunday, 1 December 2024 1:19 PM
To: [email protected] <[email protected]>
Subject: Re: [RacalRadio] Racal RA-6790GM/R2174 New to Me
?
Are the "string" wires different from regular electroluminscent panels?? Those
run at about 120 VAC 400 Hz which is pretty easy to create without much EMI.


On 11/30/2024 9:15 PM, Peter E via groups.io wrote:
> Hi Dan,
>
> I just looked up some info on electroluminescent wire. It needs to be driven
> with high frequency AC at a fairly high voltage. Not something you would want
> anywhere near a sensitive receiver I would think.
>
> Cheers,
> Peter
> --------------------------------------------------------------------------------
> *From:* [email protected] <[email protected]> on behalf of Dan Rae via
> groups.io <danrae@...>
> *Sent:* Sunday, 1 December 2024 9:37 AM
> *To:* [email protected] <[email protected]>
> *Subject:* Re: [RacalRadio] Racal RA-6790GM/R2174 New to Me
> On 11/30/2024 1:27 PM, Peter E via groups.io wrote:
>> Hi Dan,
>> Absolutely correct - I actually meant to say NiMh (must be getting old).
> And of course I did mean /less/ prone to leakage :^)? Even older.
>> I like your led lighting solution. I also wonder if it is possible to use
>> that electroluminescent "string" that is available in various places? That
>> would give really even illumination
>
> Two things there, first there is not a lot of height between the existing
> board and the front panel, so not a lot of room for those strips.? Secondly
> you need the small surface mount LEDs that shine sideways to light the LCDs.?
> The original LED lighting on the GM needed a re-worked acrylic piece to
> accommodate the only LEDs that were available at the time.
>
> I've done a few like that, the only advice I'd give would be to buy some extra
> LEDs, since they have a habit of jumping off the board never to be seen again.
>
> 73 - Dan
>
>






Re: Racal RA-6790GM/R2174 New to Me

 

Are the "string" wires different from regular electroluminscent panels?? Those run at about 120 VAC 400 Hz which is pretty easy to create without much EMI.

On 11/30/2024 9:15 PM, Peter E via groups.io wrote:
Hi Dan,

I just looked up some info on electroluminescent wire. It needs to be driven with high frequency AC at a fairly high voltage. Not something you would want anywhere near a sensitive receiver I would think.

Cheers,
Peter
--------------------------------------------------------------------------------
*From:* [email protected] <[email protected]> on behalf of Dan Rae via groups.io <danrae@...>
*Sent:* Sunday, 1 December 2024 9:37 AM
*To:* [email protected] <[email protected]>
*Subject:* Re: [RacalRadio] Racal RA-6790GM/R2174 New to Me
On 11/30/2024 1:27 PM, Peter E via groups.io wrote:
Hi Dan,
Absolutely correct - I actually meant to say NiMh (must be getting old).
And of course I did mean /less/ prone to leakage :^)? Even older.
I like your led lighting solution. I also wonder if it is possible to use that electroluminescent "string" that is available in various places? That would give really even illumination
Two things there, first there is not a lot of height between the existing board and the front panel, so not a lot of room for those strips.? Secondly you need the small surface mount LEDs that shine sideways to light the LCDs.? The original LED lighting on the GM needed a re-worked acrylic piece to accommodate the only LEDs that were available at the time.

I've done a few like that, the only advice I'd give would be to buy some extra LEDs, since they have a habit of jumping off the board never to be seen again.

73 - Dan
Re: Racal RA-6790GM/R2174 New to Me

 

开云体育

Hi Dan,

I just looked up some info on electroluminescent wire. It needs to be driven with high frequency AC at a fairly high voltage. Not something you would want anywhere near a sensitive receiver I would think.

Cheers,
Peter

From: [email protected] <[email protected]> on behalf of Dan Rae via groups.io <danrae@...>
Sent: Sunday, 1 December 2024 9:37 AM
To: [email protected] <[email protected]>
Subject: Re: [RacalRadio] Racal RA-6790GM/R2174 New to Me
?
On 11/30/2024 1:27 PM, Peter E via groups.io wrote:
Hi Dan,
?
Absolutely correct - I actually meant to say NiMh (must be getting old).
And of course I did mean less prone to leakage :^)? Even older.
?
I like your led lighting solution. I also wonder if it is possible to use that electroluminescent "string" that is available in various places? That would give really even illumination

Two things there, first there is not a lot of height between the existing board and the front panel, so not a lot of room for those strips.? Secondly you need the small surface mount LEDs that shine sideways to light the LCDs.? The original LED lighting on the GM needed a re-worked acrylic piece to accommodate the only LEDs that were available at the time.

I've done a few like that, the only advice I'd give would be to buy some extra LEDs, since they have a habit of jumping off the board never to be seen again.

73 - Dan
Re: Racal RA-6790GM/R2174 New to Me

 

开云体育

On 11/30/2024 1:27 PM, Peter E via groups.io wrote:
Hi Dan,
?
Absolutely correct - I actually meant to say NiMh (must be getting old).
And of course I did mean less prone to leakage :^)? Even older.
?
I like your led lighting solution. I also wonder if it is possible to use that electroluminescent "string" that is available in various places? That would give really even illumination

Two things there, first there is not a lot of height between the existing board and the front panel, so not a lot of room for those strips.? Secondly you need the small surface mount LEDs that shine sideways to light the LCDs.? The original LED lighting on the GM needed a re-worked acrylic piece to accommodate the only LEDs that were available at the time.

I've done a few like that, the only advice I'd give would be to buy some extra LEDs, since they have a habit of jumping off the board never to be seen again.

73 - Dan
Re: Racal RA-6790GM/R2174 New to Me

 

Hi Dan,
?
Absolutely correct - I actually meant to say NiMh (must be getting old).
?
I like your led lighting solution. I also wonder if it is possible to use that electroluminescent "string" that is available in various places? That would give really even illumination. I also like the idea that there are no more heat generating bulbs anywhere near the edge of the very hard to get LCD displays.
?
Cheers,
Peter
Re: Racal RA-6790GM/R2174 New to Me

 

Hi Tom.
?
Mine appears to be a bit later than yours - Serial 5372 on both the front and rear plates - I wonder why yours are different?
?
Dan is absolutely correct, I meant to say NiMh (not Nicad). Actually Nicads are quite hard to get now days, and I much prefer to have the battery pack wired to the board but in a separate location somewhere where leakage can't cause any grief.
?
Cheers,
Peter - VK2AN
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