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tra3900 amu fault finding

 

Hi

I have a tra3900 vhf set which has high harmonic content on when the bnc socket is in use (-20 to -30dBc). If the whip is in use the transmit is clean with harmonics better than -60dBc. I am suspecting a failed bias transistor, cap or possibly pin diode in the amu. The 85V rail is good. I wonder, does anybody have a drawing of the amu from yeoman or panther radios? It would make the search easier, it's all rather smt inside it.

Kind regards

George

G8MAU
Re: TRA976 MA991 layout drawing

 

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Andy,
The attached is slightly better, if zoomed in (but not by much). ?Not the easiest manuals to copy, as they really need an A3 scanner, which I don’t have.

73

Al

G8LIT




On 17 Jun 2020, at 19:59, Richard Hankins <g7rvi@...> wrote:

?

Andy,

well I have one, but its not a wonderful copy.??? See enclosed - it may help.?? If not - someone may have a better one.


Richard

G7RVI

On 17/06/2020 16:48, Andy wrote:
Hello
?????? Can anyone provide me with a copy of the layout of the MA991 PCB for the TRA967 radio please? Mine is driving me mad trying to work out what component is which. My sight not being good, it's making it a very long job getting this radio to work.
Thank you Andy G7BAV
_._,_._,_
Re: TRA976 MA991 layout drawing

 

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Andy,

well I have one, but its not a wonderful copy.??? See enclosed - it may help.?? If not - someone may have a better one.


Richard

G7RVI

On 17/06/2020 16:48, Andy wrote:

Hello
?????? Can anyone provide me with a copy of the layout of the MA991 PCB for the TRA967 radio please? Mine is driving me mad trying to work out what component is which. My sight not being good, it's making it a very long job getting this radio to work.
Thank you Andy G7BAV

TRA976 MA991 layout drawing

 

Hello
?????? Can anyone provide me with a copy of the layout of the MA991 PCB for the TRA967 radio please? Mine is driving me mad trying to work out what component is which. My sight not being good, it's making it a very long job getting this radio to work.
Thank you Andy G7BAV
RA3701

 

Dear colleagues, I’m posting this behalf of a good friend of mine who is looking for a IF/AF Module of the Racal RA3701 receiver.

If anyone can help then it would be really appreciated,

Kind regards Spence de M0STO

Sent whilst mobile
Re: PRM-4021

 

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Hi Anton,
?
Thank you very much.?
?
Regards
?
?
Stephen
Re: PRM-4021

 

Stephen,

Maybe I can help You for front panel assembly but don't hold Your breath I need to repair at least a dozen this thing for emergency and SAR team before I have a key to warehouse full of forgotten radio in various brand and type from "You know who"

??
Re: PRM-4021

 

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Hi Anton,
?
?
Glad the manual will be of use.
?

I have not used my PRM4021 for a year because all the frequency control knobs are broken.

?

?
Regards
?
?
?
Stephen
Re: PRM-4021

 

Hi Stephen Thompson,

Really really appreciate Your help?

Regards, 73
Anton??
Re: PRM-4021

 

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Hi Anton Moehammad via groups.io
?
?
Just uploaded PRM4021 Tech Manual
?
Best 73s
?
?
stephen thompson
New file uploaded to [email protected]

[email protected] Notification
 

Hello,

This email message is a notification to let you know that the following files have been uploaded to the Files area of the [email protected] group.

Uploaded By: racal567@...

Description:
PRM 4021 Tech Manual

Cheers,
The Groups.io Team
PRM-4021

 

Hi All,

I need help to find a service manual for my PRM-4021 I only have not so complete ultra low quality scan file of schematic diagram

Thank You,
Anton?
New file uploaded to [email protected]

[email protected] Notification
 

Hello,

This email message is a notification to let you know that the following files have been uploaded to the Files area of the [email protected] group.

Uploaded By: Richard Hankins <g7rvi@...>

Description:
Racal PRM4031 technical manual, issue 3.5, 1981

Cheers,
The Groups.io Team
New file uploaded to [email protected]

[email protected] Notification
 

Hello,

This email message is a notification to let you know that the following files have been uploaded to the Files area of the [email protected] group.

Uploaded By: Richard Hankins <g7rvi@...>

Description:
Racal PRM4031 technical manual, issue 10, August 1986

Cheers,
The Groups.io Team
Re: PRM4031

 

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Peter,

I have a PRM 4031 and I found some info on the web. I have it on the PC somewhere, I will look for it tomorrow and see what I have.

Mine has a fault on the synth board which I have been unable to find. I am using an external VFO which makes using the radio much easier.

Geoff

On 03/06/2020 16:00, Peter wrote:

Dear All,
pleased to join your group, I’ve been a member of VMARS for many years now and have an extensive collection of WW2 radios.
I have a PRM4031 radio which has just failed and am urgently needing to obtain a manual or disc for this radio.
i tried to mail Keith Watt, but it kept bouncing back!
Hope you are able to help

Regards
Peter Jones G8CDC
mob 07788 417 300

PRM4031

 

Dear All,
pleased to join your group, I’ve been a member of VMARS for many years now and have an extensive collection of WW2 radios.
I have a PRM4031 radio which has just failed and am urgently needing to obtain a manual or disc for this radio.
i tried to mail Keith Watt, but it kept bouncing back!
Hope you are able to help

Regards
Peter Jones G8CDC
mob 07788 417 300
Re: Pye Solent PTC984

 

What else do you need to know?
Re: Pye Solent PTC984

 

Hi JB

Yes got those hand drawn diagrams thanks.

Dave g1jwg
Re: Pye Solent PTC984

 

Have you checked out;? RADIOMUSEUM.org

?

Regards

JB.
Re: VRM 5090 need value of R80

 

thank you? !! ? I knew? it was a low value as its was crispy,? a tantalum of course shorted and pulled what ever is on the trace to ground ?
we will see if it works after i replace all of the 4.7 uf caps and the fuse resistor.?

the rest of the radio works well , this is one of the KAPSCH made units

WD8AXA
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