Re: Info or schematics for BBC AM9, AM7, UN4/6, AM1/57 Modules anyone?

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mrclunk

Well-known member
Joined
Nov 29, 2006
Messages
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Location
London
We've had a load of various ex BBC modules in the store cupboard for a while now and its  about time they were put to some use! But i can't find any schematics, pinouts etc..

Does anyone have any? or maybe someones has some experience of these they'd like to share.

Modules :-
AM9/6/#153 Dual Mic Amps
AM7/4/#316 Line receiving amps
AM7/2/#397 line sending amps
EQ3/15/#130 Equaliser Variable
UN6/2 Monitoring Unit
PS2/9 Power Supplys
PS2/49  Power Supplys

+ rack cases for them to go in.

I'll post some pictures tomorrow when i have a camera.
There all very nicely made, input/ output trans, indestrutable switches etc...

Any help much appreciated.
Paul
 
Hi Paul,

Is the AM9/6 fully transistorised? I have the service info. for the AM9/5 which may help (possibly not much difference).

I have the sheets for the AM7/4 (20-60dB gain, 600 Ohms input impedance, 55 Ohms out.).

I also have the sheets for the AM7/2 (fixed 10dB gain, 600 Ohms in and out).

I can't seem to find the EQ3/15. Is it audio or video?

The UN6/2 is most likely a telephone line monitoring unit, unless you know otherwise. I only have the UN1 and UN10 sheets.

I have both the power supply sheets. (PS2/9 = -24.5V @ 500mA, PS2/49 = same but @ 750mA). Both suitable for transistorised audio amps.

Regards,

Roddy
 
Hi Roddy,
Thanks for getting back to me.

Yes the AM9/6 is transistor with two pres in one module.
Even if the AM9/5 manuals not exactly the same I’m sure it'll set me off in the right direction.

The Eqs audio, it has a white face as opposed to the grey of the other units. This is actually the bit im most interested in getting going. I've two of them so could be very useful.

The UN6/2 is just a small patch bay I believe, don’t worry about it. I may use it for patching some effects units as we're fast running out of tie lines to the desk pbay.

Power supply sheets will be great as they will need a full recap, think they were sat in a garage for 10+ years.
How can I get all the sheets off you? Are they PDF's?

Many thanks and all the best
Paul
 
That sounds like an interesting lot.

It's a shame you need a patchbay - we were throwing out quite a few nice PO jack models recently but I only took a couple. I kept saying to myself "you'll never need these". Now I cringe and think of the rest sitting in a bin.

The sheets are on paper in a book, and some pages are A3, so I'll maybe see if I can photocopy them for you. Otherwise, I may see if I can photo them once I get a new digital camera.

Roddy
 
Ok, fantastic.
When you have a minute Photo copys or pics would be great.
Are they in a published book or is it an internal BBC thing?
Do u know of any unused/unloved copys floating about that someone might sell me?
I'm thinking it would be handy for the future. I saw a load of similar BBC modules sell on eby recently, for next to nothing.
regards
paul
 
Hi, :grin:

Thoses seems to be very nice :thumb: ,I'll be very interested to see the datasheet of the AM7/4 AM7/2 and AM9/6 if it's possible Please.

Great.
Best regards,b2.
 
Hi.

I also have the AM9/6 mic pre and the smaller power supply.
I could get you the pin out for those if you want.
Used to have the schematics for both, but my tech has lost them :cry:
 
API,
The pinouts would be very handy to get me going.
I'll probably just build a quick PSU to test , before i restore the originals. Crusty old power supplies scare me!
Think i read some where they run on +/- 24V is that right?

Do they get alot of use in your studio?
Do they shine with a particular mic/source?
 
[quote author="mrclunk"]Ok, fantastic.
When you have a minute Photo copys or pics would be great.[/quote]

Cool. I'll try and do it soon.

Are they in a published book or is it an internal BBC thing?

It's an internal thing for the engineers.

Do u know of any unused/unloved copys floating about that someone might sell me?

No! :razz:

I will try and help anyone who owns a specific piece of gear though.

Roddy
 
[quote author="synthi"]
Maybe you have something about the AM7/13 (high gain line amp)?
[/quote]

Yes. In fact, I'd like to discuss this....

The amp has 62db gain and has a 1:1.3 transformer balanced 18K input. I'd like to know if we could simply replace this transformer for say a 1:5 mic input transformer to provide 76dB gain and a ~1K input impedance.

Suggestions?
 
62dBs? wow! :shock: Its really a high gain line amp...

Then I think using a mic input trafo will work without problems...

About the gain, the front panel pot only gos -6 to +6 dB, but I think the total gain in the preamp is done by a external resistor? So maybe using a switch with resistors is the way to go for gain.

Schematics??? :thumb:

Synthi
 
[quote author="synthi"]
Schematics??? :thumb:
[/quote]

Do you have any AM7/13s ? :razz:

I am quite fussy about what I do with schematics! I have them on A3 paper in a book, so I would need to see.

Roddy
 
Yes Roddy, I got a rack some years ago with 4x AM9/19Bs and 4x AM7/13.
I have the info on the 9/19s and the prontpanel for racking is almost done, but no luck (til now!!) with the 7/13s :)

Maybe you can take a photo at good resolution for the large A3 sheet instead of scan it?

Thanks!

Synthi
 
[quote author="synthi"]
Maybe you can take a photo at good resolution for the large A3 sheet instead of scan it?[/quote]

Cool. I currently have a 2MP Nikon which may be ok if I store it as a .tiff. However, I've been offered a 4MP version of the same camera which would probably be good enough. Otherwise, I could mail you photocopies in a letter.

I will PM you.

Roddy
 
Thanks a lot Roddy!

I have a 4M fuji camera and using a good lights is fine for large A3 papers, readable resolution when using max quality, even in jpg format at shooting.

Synthi
 
I found a picture of the EQ3/15, maybe it'll help in identifying a similar model/schematic.
Have some down time at the end of the week, which would give me an opportunity to them going.

Also found this page. http://www.bbceng.info/Designs/designs_EDI_sheets/EDI_sheets.htm
Spreadsheets listing hundreds of BBC Designs and links to PDF Spec Sheets. (the PDF's take a while to DL)
There’s a lot of interesting BBC info/history on the main site too.

BBC%20EQ%203%2015.JPG

cheers
Paul
 
Hi guys,

Just to say, sorry for the delay. I am very busy training just now and have little time at the weekend (and I'm away in the middle of nowhere during the week).

I will get scans soon.


Roddy
 
nice one Roddy,
please make sure you get your priorities straight though. ie Pub, John Shuttleworth marathon first.
 
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