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 26th Jun 2022, 8:35 am   #1
Masterclock
Diode
 
Join Date: Sep 2021
Location: Aberdeen, Aberdeeshire, Scotland, UK.
Posts: 3
Default Rotary Transformers

Hi, I'm currently restoring a 1950's Marconi AD118 HF radio. This was an airborne MF and HF radio and used a rotary transformer to generate B+ 230VDC from the nominal 28VDC aircraft supply. A previous owner has removed the transformer and had replaced it with a mains transformer. I'd like to convert the radio back to 28VDC operation and have just rewired all the heaters back to the original series/ parallel arrangement. Just working through all the high resistance and open circuit anode resistors at the moment. I'm looking for a suitable DC-DC converter to replace the rotary converter, needs to supply 225-230VDC at about 200mA. Any suggestions?

Cheers,

Ian
Masterclock is offline  
Old 26th Jun 2022, 11:28 am   #2
Peter.N.
Dekatron
 
Join Date: Jul 2008
Location: Charmouth, Dorset, UK.
Posts: 3,601
Default Re: Rotary Transformers

Just after the war the government surplus shops were full of them, had quite a few myself, I doubt that they are made now, I think your only chance is to find someone who has one left over. Have you had a look on Ebay? I have only seen big 3 phase things on there but if you put a 'saved search' on there you never know.

Peter
Peter.N. is offline  
Old 26th Jun 2022, 1:59 pm   #3
Cobaltblue
Moderator
 
Cobaltblue's Avatar
 
Join Date: Dec 2010
Location: Exeter, Devon and Poole, Dorset UK.
Posts: 6,824
Default Re: Rotary Transformers

You could try this one

https://www.ebay.co.uk/itm/334303192...sAAOSwr9xh7pGy

I always find its easier to search Dynamotor rather than the term I prefer which is Rotary Transformer.

or perhaps this one

https://www.ebay.co.uk/itm/353627395...8AAOSw0X9hGpmD

https://www.ebay.co.uk/itm/284227956...QAAOSwRrtgV8f-

Good luck hope you find something suitable

Cheers

Mike T
__________________
Invisible airwaves crackle with life or at least they used to
Mike T BVWS member.
www.cossor.co.uk
Cobaltblue is online now  
Old 26th Jun 2022, 5:49 pm   #4
Masterclock
Diode
 
Join Date: Sep 2021
Location: Aberdeen, Aberdeeshire, Scotland, UK.
Posts: 3
Default Re: Rotary Transformers

Thanks for the responses so far, but I think I didnt explain. I want to replace the rotary transformer, dynomotor with a solid state DC-DC inverter to do the same job. I have been playing with a couple of Chinese modules, but the hash and noise that comes out of them is horrendus. Without shielding them inside a can and adding extra filtering I wondered if anyone could sugest an alternative?

Cheers,

Ian
Masterclock is offline  
Old 26th Jun 2022, 8:42 pm   #5
Masterclock
Diode
 
Join Date: Sep 2021
Location: Aberdeen, Aberdeeshire, Scotland, UK.
Posts: 3
Default Re: Rotary Transformers

Sorry, I didn't word that too well. I'm looking for a solid state inverter, DC-DC converter, 28VDC to 225-230VDC, to replace the missing Dynamotor.
Masterclock is offline  
Old 27th Jun 2022, 11:19 am   #6
Peter.N.
Dekatron
 
Join Date: Jul 2008
Location: Charmouth, Dorset, UK.
Posts: 3,601
Default Re: Rotary Transformers

Ah, OK I thought you wanted to restore it to original spec.

Peter
Peter.N. is offline  
Old 27th Jun 2022, 7:48 pm   #7
Ed_Dinning
Dekatron
 
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,173
Default Re: Rotary Transformers

Hi Ian, you may find modern MIL inverters listed on the auction site. These should be extreamly well filtered

Ed
Ed_Dinning is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 3:34 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.