UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Amateur and Military Radio

Notices

Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment.

Closed Thread
 
Thread Tools
Old 20th Sep 2020, 8:53 am   #1
trh01uk
Octode
 
trh01uk's Avatar
 
Join Date: Nov 2010
Location: Ross-on-Wye, Herefordshire, UK.
Posts: 1,648
Default Anyone recognise this naval equipment?

I picked up the attached photos of this "Amplifier A/S 31" on a facebook post recently - a piece of naval equipment I've not seen before. I think there are some intriguing elements to the schematic - but I will let others comment before pointing them out.

Obviously Collingwood might well say exactly what it was for, and what equipment it was part of - and I have recommended the owner gets in touch with them.

Richard
Attached Thumbnails
Click image for larger version

Name:	A_S-31_front2.jpg
Views:	273
Size:	55.4 KB
ID:	216020   Click image for larger version

Name:	A_S-31_front.jpg
Views:	243
Size:	74.1 KB
ID:	216021   Click image for larger version

Name:	A_S-31_schematic.jpg
Views:	222
Size:	46.5 KB
ID:	216022  
trh01uk is offline  
Old 20th Sep 2020, 2:09 pm   #2
M0FYA Andy
Nonode
 
Join Date: May 2007
Location: Preston, Lancashire, UK.
Posts: 2,510
Default Re: Anyone recognise this naval equipment?

Richard,

I wonder what 'A/S' means?
I have an odd Admiralty unit, Receiver A/S 324, which I'm struggling to find anything on. Dated 1944, a rather anonymous steel box, it looks to be a VLF TRF receiver.
Searching the Collingwood website, which I find to be very unfriendly, doesn't throw up 'A/S'.

Andy
M0FYA Andy is offline  
Old 20th Sep 2020, 2:31 pm   #3
trh01uk
Octode
 
trh01uk's Avatar
 
Join Date: Nov 2010
Location: Ross-on-Wye, Herefordshire, UK.
Posts: 1,648
Default Re: Anyone recognise this naval equipment?

Andy,

well, fully agreed on the unfriendliness of the Collingwood website. Its got an absolute mine of information in it - but finding anything specific is a total nightmare. I have had a good rummage but failed to turn up anything with the prefix "A/S". Plenty of other amplifiers of course.

Looking elsewhere on the web does suggest that "A/S" might stand for "anti-submarine". An example of that is given here: https://en.wikipedia.org/wiki/Loch-class_frigate

I've analysed the circuit to some extent, and I believe it to be a TRF receiver, with a heterodyne oscillator mixing in a semiconductor rectifier, followed by a couple of audio stages. Looking at the tuned circuits, the capacitor values are suggestive - given that the variable is 7nF (!!! - how big is that brute??) and you can switch in up to 3 more 6nF capacitors. So we have a total of some 25nF. So the frequency range is probably down to 13kHz or so. And that would be typical of submarines, which I understand can transmit submerged on such extremely long wavelengths. That would mean the figures on the dials - which I can't read (too blurry) are probably in kHz).

Further clues are that there is only one RF stage, but in front of it is a hefty resistive attenuator. If a submarine was close - the field strength from a powerful transmitter might be extremely high. And if it wasn't close I presume the ship wouldn't be that interested.....

Richard
trh01uk is offline  
Old 20th Sep 2020, 3:01 pm   #4
ThePillenwerfer
Octode
 
ThePillenwerfer's Avatar
 
Join Date: Mar 2011
Location: Sheffield, South Yorkshire, UK.
Posts: 1,453
Default Re: Anyone recognise this naval equipment?

No idea what it is but agree that A/S is most likely Anti-Submarine.
ThePillenwerfer is offline  
Old 20th Sep 2020, 3:15 pm   #5
ms660
Dekatron
 
ms660's Avatar
 
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
Default Re: Anyone recognise this naval equipment?

What's the Admiralty Pattern number?

Lawrence.
ms660 is offline  
Old 20th Sep 2020, 3:36 pm   #6
Gridiron
Heptode
 
Join Date: Apr 2010
Location: West Midlands, UK.
Posts: 659
Default Re: Anyone recognise this naval equipment?

Could it be something to do with ASDIC, the frequencies seem to be similar.
Gridiron is offline  
Old 20th Sep 2020, 3:41 pm   #7
ionburn
Heptode
 
ionburn's Avatar
 
Join Date: Dec 2014
Location: Lincoln, Lincolnshire, UK.
Posts: 583
Default Re: Anyone recognise this naval equipment?

I would agree. A/s is accepted as anti submarine and because of the frequency it could be sonar but the only circuitry I have to hand is American.
ionburn is offline  
Old 20th Sep 2020, 4:12 pm   #8
DMcMahon
Dekatron
 
DMcMahon's Avatar
 
Join Date: Apr 2019
Location: Worthing, West Sussex, UK.
Posts: 6,587
Default Re: Anyone recognise this naval equipment?

Way back for a long time I worked on Naval Sonar systems, a few of the very old ones were designated A/S xxx for Anti Submarine.

Never come across A/S 31 though, a wild guess is that it is pre 1950.

David
DMcMahon is offline  
Old 20th Sep 2020, 5:01 pm   #9
HamishBoxer
Dekatron
 
HamishBoxer's Avatar
 
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 8,923
Default Re: Anyone recognise this naval equipment?

These are 1930,s 2 volt valves,certainly the PM3 is.(Equiv NR15)
__________________
G8JET BVWS Archivist and Member V.M.A.R.S
HamishBoxer is offline  
Old 20th Sep 2020, 5:02 pm   #10
barrymagrec
Octode
 
Join Date: Dec 2017
Location: Morden, Surrey, UK.
Posts: 1,552
Default Re: Anyone recognise this naval equipment?

Certainly is from the valves - PM4DX and PM24A.

From my Dad`s handwritten Navy / Army / Air Force / Commercial equivalents book which pre-dates CV types.
barrymagrec is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 3:41 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.