?
Hello Alan
?????? Ok, thank you.
I can understand the moderators not wanting to put info into public, but it's
not very helpful at times.
As the 350 was a Plessey design, I did not expect
to see Racal on the drawings. But the MOD did let contracts in a very odd
way!
The custom chips for some of the Clansman kit was
made at the Plessey semicon factory about 10 miles from me. I think the overlays
etc still exisit to make the chips, but not a cheap thing to do.
?
?
???? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? Thanks again
??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? Andy G7BAV
----- Original Message -----
Sent: Friday, October 11, 2024 5:02
PM
Subject: Re: [RacalRadio] Uk/PRC350
Andy,?
Sorry about that; I just realised that Groups.io helpfully resized the
pics I attached enough to blur any useful detail: my local copy was as sent,
but unreadable once logged in to the Groups.io interface.
I¡¯ve re-sent the pics direct to you, at full definition, so they should
be as readable as possible; they¡¯re from a copy, of a copy of a Racal factory
manual, so not very good in the first place, unfortunately. ?Hopefully
just the big capacitors, or a bad joint, and not the tiny Unobtainium Plessey
chip!
?
73,
?
Al
G8LIT?
|
Re: Audio amp for 6217A receiver
Let me start by saying that this project is driving me crazy.? It shouldn't be this hard, but somehow, I just have a block.
?
In order to power the LM380 board from the receiver, I have to connect the violet (reg -18V) wire from the receiver power supply to the LM380 board ground, and a ground connection from the receiver chassis to pin 14 of the LM380.? That requires me to float the LM380 board on insulated standoffs because the board ground is at -18V relative to the receiver chassis ground..? I should be able to isolate the speaker jack by using an insulated sleeve jack for the audio output, and connecting the audio output to the tip and the LM380 circuit board ground (which is actually the DC +18V line) to the sleeve.? That way, the audio output jack will be floating and not connected to the receiver chassis at all.
?
The audio input is a shielded cable with the shield connected to the chassis ground in the receiver.? Because the receiver uses positive ground, the chassis is connected to the + terminal from the power supply.
I can't connect the incoming audio ground (+18V) to the LM380 board ground (-18V).
?
So how do I need to connect the shielded cable from the receiver to the input of the LM380 amp?
?
Thanks for your insight!? I really could use some help here!
Mike, WB0LDJ
mharmon at att dot net
|
Andy,?
Sorry about that; I just realised that Groups.io helpfully resized the pics I attached enough to blur any useful detail: my local copy was as sent, but unreadable once logged in to the Groups.io interface.
I¡¯ve re-sent the pics direct to you, at full definition, so they should be as readable as possible; they¡¯re from a copy, of a copy of a Racal factory manual, so not very good in the first place, unfortunately. ?Hopefully just the big capacitors, or a bad joint, and not the tiny Unobtainium Plessey chip!
?
73,
?
Al
G8LIT?
|
?
Hello Alan
?????? Sorry when I
try to open the attched, I can't see any detail. It's just a fuzzy blur. Could
you try sending each as an attachment please? Or I would be happy to pay you
photo copy and post to me if you could please?
?
?
?
??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
Thank you
??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? Andy G7BAV
----- Original Message -----
Sent: Thursday, October 10, 2024 5:20
PM
Subject: Re: [RacalRadio] Uk/PRC350
Andy,
Please see attached; I¡¯d test the big smoothing caps for high ESR, or
other problems, especially the one on the 9V rail, that provides feedback to
the custom chip? ?In recent years, I¡¯ve found bad solder joints on the
bigger caps, possibly from 40 years of temperature cycling, so could be worth
having a close look at the soldering?
73
?
Al
G8LIT
|
?
Hello Alan
?????? Ok, thank you.
Thanks for the info, and your experinace of problems.
?
?
?????????????????
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? Thank you
??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ???
??? ??? ??? ??? Andy
G7BAV
----- Original Message -----
Sent: Thursday, October 10, 2024 5:20
PM
Subject: Re: [RacalRadio] Uk/PRC350
Andy,
Please see attached; I¡¯d test the big smoothing caps for high ESR, or
other problems, especially the one on the 9V rail, that provides feedback to
the custom chip? ?In recent years, I¡¯ve found bad solder joints on the
bigger caps, possibly from 40 years of temperature cycling, so could be worth
having a close look at the soldering?
73
?
Al
G8LIT
|
Andy,
Please see attached; I¡¯d test the big smoothing caps for high ESR, or other problems, especially the one on the 9V rail, that provides feedback to the custom chip? ?In recent years, I¡¯ve found bad solder joints on the bigger caps, possibly from 40 years of temperature cycling, so could be worth having a close look at the soldering?
73
?
Al
G8LIT
|
Hello Scott
Thank you. Yes, I did think it was the soft start circuit, but don't have a circuit or layout for the module.
Thanks
Andy
toggle quoted message
Show quoted text
----- Original Message ----- From: "Scott Dorsey" <kludge@...> To: < [email protected]> Sent: Thursday, October 10, 2024 12:38 PM Subject: Re: [RacalRadio] Uk/PRC350 If it tries to start but crowbars look for bad electrolytic or tantalum bypasses. --scott --- This email has been checked for viruses by AVG.
|
If it tries to start but crowbars look for bad electrolytic or tantalum
bypasses.
--scott
|
Hello, does anyone have a circuit or any information on the power module of the PRC350 please? It's module 16. Mine tries to start, but stops drawing any current. I have a block diagram, but nothing else.
Thank you
Andy G7BAV
|
Re: TRA931 Technical Service Manual
Thanks Dan,
?
What I need specificall is to fix the Transceiver board Type MA930 vs MA930X
?
Also, if anyone has a spare working XCVR Board MA930 for sale that would be great.?
?
Ilan 4X6MU
|
Re: TRA931 Technical Service Manual
On 10/6/2024 3:55 AM, Ilan via groups.io wrote: TRA931X/Y available but the plain TRA931 version couldn't find anywhere. Ilan, I'm slowly bringing a plain 931 back to life, using the X/Y manual.? The two main boards and PA board seem to be the same and the only differences I see are those connected to the two extra BNC sockets on the front panel, so pretty obvious.? So far for me the X/Y manual is fine. For what it's worth, there was a copy of the 931 made in South Africa called the Grinel TR48 and the manual for that contains details that are absent from the Racal one, for example coil winding details. 73 - Dan ac6ao / g3ncr
|
TRA931 Technical Service Manual
Hi Guys,
?
Can anyone send me a pdf file with Technical Service Manual for the TRA931.
?
TRA931X/Y available but the plain TRA931 version couldn't find anywhere.
?
Help Appreciated.
?
Best 73s
?
ILAN 4X6MU
?
|
Hi, thanks for the reply.
The capacitors on the power regulation board have been changed and the set switches on when fed with 12/14v anything over 14v and it refuses to fire up.
It is suposed to be powered between sort of 12/30v hence my thought about power regulation.
The 85v rail tested fine its rock solid at 85v and clean. I did find a Web site with rather alot of info on the set and this has been most helpful.
However I'm after a power supply board to pull apart and work through.
Kind regards martin 2E0HVE
?
|
We used a lot of tantalum capacitors on supply lines at Racal in the 1980s and every piece of Racal test equipment I've bought recently has had at least one fail, so your diagnosis looks promising!
?
--
Mike G8GYW
|
TRA3900 I think you mean.
There¡¯s a capacitor that fails on the 85V supply circuit that may be the problem on yours. ?From what I remember there can be either tantalum or electrolytic caps used there, and the tantalums are time bombs - their failure mode being a short and sometimes a bit of fireworks as they expire.?
I have some writeup explaining the location of this thing if you don¡¯t already know about it. ?Failing that, LR Series still has complete TRA3900 sets in great shape, though I don¡¯t believe he sells parts.
. Probably because I'm outside wrestling wolves.
toggle quoted message
Show quoted text
On Oct 1, 2024, at 4:37?AM, Martin 2E0HVE via groups.io <martinsimonsohn1@...> wrote:
?
Good day to all,
I'm placing a request on here with the hope of picking up some spares for a tra9300 vhf set.
I'm looking for a vehicle rack module and leads, but most importantly, I'm looking for a good power supply board as the one I own has a fault with power regulation.
Many thanks, martin 2E0HV
|
I am looking for a vehicle mount for a VRM5080 radio.
W5DTW
--
This email has been checked for viruses by Avast antivirus software.
www.avast.com
--
MOGMAN
|
Re: TRA-921 MA-924 circuit
And by the way... Price and location pls
Thanks
SergioD.
On Sep 27, 2024 14:20, "Cesar via groups.io" <Cesarleon@...> wrote:
By the way¡ I am selling one fully working?
?
|
Good day to all,
I'm placing a request on here with the hope of picking up some spares for a tra9300 vhf set.
I'm looking for a vehicle rack module and leads, but most importantly, I'm looking for a good power supply board as the one I own has a fault with power regulation.
Many thanks, martin 2E0HV
|
TRA931X Switching & Fixed Level Audio Amplifier Board
Hi guys,
I'm bringing a TRA-931 back from the dead.
On my RF board sits a piggyback board which I presume is the Switching & Fixed Level Audio Amplifier Board.
This is though, very different to the one shown in the manual. Nothing matches, pin numbers, semiconductor count, semiconductor type etc etc.
Mine is marked CD713250, yet the one in the service manual is CD713163. Is there a schematic for the type of board I have?
|
Re: Sales of Racal Gear Permitted here?
Hi Duncan thank you for the explanation so not in the UK It¡¯s the VAT and Duty that are causing big problems when buying second hand equipment apparently this is not the case with other items ? Regards Paul ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Craig Tully
Sent: 30 September 2024 13:06
To: [email protected]
Subject: Re: [RacalRadio] Sales of Racal Gear Permitted here?? AK= Alaska On 9/30/2024 3:34 AM, Duncan Hawkins wrote: AK = Arkansas, TX = Texas ? Thank you Craig?? but? AK? and TX? is as clear as MUD? so question remains unanswered Regards Paul ? ? According to QRZ he is in AK, long, long way from TX :) On 9/29/2024 8:12 PM, Paul Bicknell wrote: Hi what¡¯s your location ? From: [email protected] [mailto:[email protected]] On Behalf Of KL7AM
Sent: 28 September 2024 16:49
To: [email protected]
Subject: [RacalRadio] Sales of Racal Gear Permitted here? ? Have some Racal gear to sell and can I post it here?
--
MOGMAN
--
MOGMAN
|
Mike
Tone