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Newbie question on LF adapters


Pete Connors G4PLZ
 

Greetings to all

Last having owned a RA17 in the 1970s, I have acquired a clean looking RA117E to refurbish.
I would like to accompany this eventually with an LF converter, ideally the RA237, but if I used an RA137 the only difference appears to be the 2Mhz crystal notch somewhere around the cathode follower. I cannot locate a circuit diagram to check the actual configuration but it does not seem too problematic to add a 2MHz xtal notch to an RA137.
Does anybody have a circuit diagram of the RA237? Or can anybody tell me how much the use of an unmodified RA137 would compromise performance?

Best regards,
Pete Connors G4PLZ


 

Hello Peter,

Attached you will find the requested pictures; the RA 137A is the British version.
I can supply a mains cable with a matching 3-pole connector and may be I can find some RF-cables, but that will take some searching time.
I cannot help you with a schematic for the 237 (my 137A will come with a copy of the original manual.
(But I found good information on the restauration of a 237; see attached PDF).

In the past I had plans to restore an RA117E together with a RA137A, and a RA63A or RA98A, but my health has seriously restricted this part of my hobbies.
It does mean, that I have not done any work on the 117E and subsequently, I have been unable to test the 137A or any of the other equipment,
so I am offering the RA137A-1 "as is" for € 60,00 including packaging but excluding transport to the UK

The following websites may contain more info on the 237, but I could not find any schematics there:
search for racal
again, search for racal

PayPal is ok for me.
Let me know about your plans.

Best regards,

Cees Bekkers


-----Oorspronkelijk bericht-----
Van: [email protected] <[email protected]> Namens Pete Connors G4PLZ
Verzonden: woensdag 23 november 2022 12:22
Aan: [email protected]
Onderwerp: [RacalRA17forum] Newbie question on LF adapters

Greetings to all

Last having owned a RA17 in the 1970s, I have acquired a clean looking RA117E to refurbish.
I would like to accompany this eventually with an LF converter, ideally the RA237, but if I used an RA137 the only difference appears to be the 2Mhz crystal notch somewhere around the cathode follower. I cannot locate a circuit diagram to check the actual configuration but it does not seem too problematic to add a 2MHz xtal notch to an RA137.
Does anybody have a circuit diagram of the RA237? Or can anybody tell me how much the use of an unmodified RA137 would compromise performance?

Best regards,
Pete Connors G4PLZ


 

Hi Pete,

I have the original Racal manual for the RA-237B (North American version).
I am surprized that it is not available on BAMA.
Providing that I find some time to do it, I can put it on the scanner bed
and provide you with a .pdf copy.

Let me know if you are interested.

73, Jacques, VE2JFE in Montreal

-----Message d'origine-----
De?: [email protected] <[email protected]> De la part de Pete
Connors G4PLZ
Envoy¨¦?: 23 novembre 2022 06:22
??: [email protected]
Objet?: [RacalRA17forum] Newbie question on LF adapters

Greetings to all

Last having owned a RA17 in the 1970s, I have acquired a clean looking
RA117E to refurbish.
I would like to accompany this eventually with an LF converter, ideally the
RA237, but if I used an RA137 the only difference appears to be the 2Mhz
crystal notch somewhere around the cathode follower. I cannot locate a
circuit diagram to check the actual configuration but it does not seem too
problematic to add a 2MHz xtal notch to an RA137.
Does anybody have a circuit diagram of the RA237? Or can anybody tell me how
much the use of an unmodified RA137 would compromise performance?

Best regards,
Pete Connors G4PLZ


 

RA237B manual (with schematic) attached.

Gerry O'Hara VE7GUH (author of the article)

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Hawkeye via groups.io
Sent: November 23, 2022 7:25 AM
To: [email protected]
Subject: Re: [RacalRA17forum] Newbie question on LF adapters

Hello Peter,

Attached you will find the requested pictures; the RA 137A is the British version.
I can supply a mains cable with a matching 3-pole connector and may be I can find some RF-cables, but that will take some searching time.
I cannot help you with a schematic for the 237 (my 137A will come with a copy of the original manual.
(But I found good information on the restauration of a 237; see attached PDF).

In the past I had plans to restore an RA117E together with a RA137A, and a RA63A or RA98A, but my health has seriously restricted this part of my hobbies.
It does mean, that I have not done any work on the 117E and subsequently, I have been unable to test the 137A or any of the other equipment, so I am offering the RA137A-1 "as is" for € 60,00 including packaging but excluding transport to the UK

The following websites may contain more info on the 237, but I could not find any schematics there:
search for racal
again, search for racal

PayPal is ok for me.
Let me know about your plans.

Best regards,

Cees Bekkers


-----Oorspronkelijk bericht-----
Van: [email protected] <[email protected]> Namens Pete Connors G4PLZ
Verzonden: woensdag 23 november 2022 12:22
Aan: [email protected]
Onderwerp: [RacalRA17forum] Newbie question on LF adapters

Greetings to all

Last having owned a RA17 in the 1970s, I have acquired a clean looking RA117E to refurbish.
I would like to accompany this eventually with an LF converter, ideally the RA237, but if I used an RA137 the only difference appears to be the 2Mhz crystal notch somewhere around the cathode follower. I cannot locate a circuit diagram to check the actual configuration but it does not seem too problematic to add a 2MHz xtal notch to an RA137.
Does anybody have a circuit diagram of the RA237? Or can anybody tell me how much the use of an unmodified RA137 would compromise performance?

Best regards,
Pete Connors G4PLZ


 

Thanks for this one, Gerry.

73, Jacques, VE2JFE in Montreal

-----Message d'origine-----
De : [email protected] <[email protected]> De la part de Gerry O'Hara
Envoy¨¦ : 23 novembre 2022 12:58
? : [email protected]
Objet : Re: [RacalRA17forum] Newbie question on LF adapters

RA237B manual (with schematic) attached.

Gerry O'Hara VE7GUH (author of the article)

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Hawkeye via groups.io
Sent: November 23, 2022 7:25 AM
To: [email protected]
Subject: Re: [RacalRA17forum] Newbie question on LF adapters

Hello Peter,

Attached you will find the requested pictures; the RA 137A is the British version.
I can supply a mains cable with a matching 3-pole connector and may be I can find some RF-cables, but that will take some searching time.
I cannot help you with a schematic for the 237 (my 137A will come with a copy of the original manual.
(But I found good information on the restauration of a 237; see attached PDF).

In the past I had plans to restore an RA117E together with a RA137A, and a RA63A or RA98A, but my health has seriously restricted this part of my hobbies.
It does mean, that I have not done any work on the 117E and subsequently, I have been unable to test the 137A or any of the other equipment, so I am offering the RA137A-1 "as is" for € 60,00 including packaging but excluding transport to the UK

The following websites may contain more info on the 237, but I could not find any schematics there:
search for racal
again, search for racal

PayPal is ok for me.
Let me know about your plans.

Best regards,

Cees Bekkers


-----Oorspronkelijk bericht-----
Van: [email protected] <[email protected]> Namens Pete Connors G4PLZ
Verzonden: woensdag 23 november 2022 12:22
Aan: [email protected]
Onderwerp: [RacalRA17forum] Newbie question on LF adapters

Greetings to all

Last having owned a RA17 in the 1970s, I have acquired a clean looking RA117E to refurbish.
I would like to accompany this eventually with an LF converter, ideally the RA237, but if I used an RA137 the only difference appears to be the 2Mhz crystal notch somewhere around the cathode follower. I cannot locate a circuit diagram to check the actual configuration but it does not seem too problematic to add a 2MHz xtal notch to an RA137.
Does anybody have a circuit diagram of the RA237? Or can anybody tell me how much the use of an unmodified RA137 would compromise performance?

Best regards,
Pete Connors G4PLZ


Pete Connors G4PLZ
 

Thank you Gerry.
For some reason I could not find that manual with an internet search. XL1 in series with C66, exactly what I was expecting.

73, Pete G4PLZ

On 23/11/2022 17:58, Gerry O'Hara wrote:
RA237B manual (with schematic) attached.

Gerry O'Hara VE7GUH (author of the article)

-----Original Message-----
From:[email protected] <[email protected]> On Behalf Of Hawkeye via groups.io
Sent: November 23, 2022 7:25 AM
To:[email protected]
Subject: Re: [RacalRA17forum] Newbie question on LF adapters

Hello Peter,

Attached you will find the requested pictures; the RA 137A is the British version.
I can supply a mains cable with a matching 3-pole connector and may be I can find some RF-cables, but that will take some searching time.
I cannot help you with a schematic for the 237 (my 137A will come with a copy of the original manual.
(But I found good information on the restauration of a 237; see attached PDF).

In the past I had plans to restore an RA117E together with a RA137A, and a RA63A or RA98A, but my health has seriously restricted this part of my hobbies.
It does mean, that I have not done any work on the 117E and subsequently, I have been unable to test the 137A or any of the other equipment, so I am offering the RA137A-1 "as is" for € 60,00 including packaging but excluding transport to the UK

The following websites may contain more info on the 237, but I could not find any schematics there:
search for racal
again, search for racal

PayPal is ok for me.
Let me know about your plans.

Best regards,

Cees Bekkers


-----Oorspronkelijk bericht-----
Van:[email protected] <[email protected]> Namens Pete Connors G4PLZ
Verzonden: woensdag 23 november 2022 12:22
Aan:[email protected]
Onderwerp: [RacalRA17forum] Newbie question on LF adapters

Greetings to all

Last having owned a RA17 in the 1970s, I have acquired a clean looking RA117E to refurbish.
I would like to accompany this eventually with an LF converter, ideally the RA237, but if I used an RA137 the only difference appears to be the 2Mhz crystal notch somewhere around the cathode follower. I cannot locate a circuit diagram to check the actual configuration but it does not seem too problematic to add a 2MHz xtal notch to an RA137.
Does anybody have a circuit diagram of the RA237? Or can anybody tell me how much the use of an unmodified RA137 would compromise performance?

Best regards,
Pete Connors G4PLZ