Warning: Creating default object from empty value in /homepages/11/d132647312/htdocs/Amfone/mkportal/include/SMF/smf_out.php on line 47
DC-DC Whatsit?




 
The AM Forum
April 16, 2021, 11:19:03 PM *
Welcome, Guest. Please login or register.

Login with username, password and session length
 
   Home   Help Calendar Links Staff List Gallery Login Register  
Pages: [1]   Go Down
  Print  
Author Topic: DC-DC Whatsit?  (Read 3259 times)
0 Members and 1 Guest are viewing this topic.
WU2D
Contributing
Member
*
Offline Offline

Posts: 1770


CW is just a narrower version of AM


« on: March 15, 2011, 08:20:17 PM »

A guy at work gave me a BC-603 receiver he had under his desk?!? Now this receiver is 1944 vintage and was the WBFM gear used late in WW2 after Normandy mostly for armor. It seems to tune from 20 to 28 MC.

It was complete with a nice manual and this strange DC-DC converter that he said was the power supply. I assume that this is some kind of 12V to HV converter and since the BC-603 runs on 12V, I suppose it could be the power supply for a mobile setup. Anybody recognize this?

Mike WU2D


* DCDC_3.jpg (403.95 KB, 2235x1929 - viewed 357 times.)

* DCDC_1.jpg (888.03 KB, 3648x2736 - viewed 471 times.)

* DCDC_2.jpg (531.1 KB, 2892x2181 - viewed 344 times.)
Logged

These are the good old days of AM
KA8WTK
Contributing
Member
*
Offline Offline

Posts: 865



« Reply #1 on: March 15, 2011, 09:24:24 PM »

IIRC, one the dynamotor supplies for the radio ran on 12 volts. There was also a dynamotor that ran on 24 volts. Both supplied 220 volts for plate power in the receiver. I would guess that the radio could be wired for 12 or 24 volts for the filament string. You would need to look at the TM for the unit.
What you have there may be a 12 to 220 volt inverter.

Logged

Bill KA8WTK
K9PNP
Member

Offline Offline

Posts: 470



« Reply #2 on: March 15, 2011, 10:26:25 PM »

Like Bill said, the BC-603 dynamotor supplied 220 VDC @ 80 ma to the receiver.  From looking at your PS, looks like a standard 2-transistor multivibrator DC-DC unit.  From the way the transformer is wired, looks like it puts out 1?5 V @ 360 ma.  Can't read the middle number on the transformer specs and none of my crossferences show that transformer.  Looks like it could be wired to put out 220 V by changing the wire from pin 3 to pin 4 unless there is something not obvious that will not handle this.

Hard to tell if it is a commercial unit or a homebrew one.  If it's homebrewed, somebody did a really good job with the heat sink.  The really fun part is wiring the filaments to operate on 12 V without the DM-34 dynamotor with its original plug.  Of course, if you have the TM with it should not be an issue.
Logged

73,  Mitch

Since 1958. There still is nothing like tubes to keep your coffee warm in the shack.

Vulcan Theory of Troubleshooting:  Once you have eliminated the impossible, whatever remains, however improbable, must be the truth.
Opcom
Patrick J. / KD5OEI
Contributing
Member
*
Offline Offline

Posts: 7780



WWW
« Reply #3 on: March 15, 2011, 11:38:23 PM »

It is homebrew, nice job. The two carbon resistors have been hot. Why not replace them with a couple of 5W sand WW's?
Logged

Radio Candelstein - Flagship Station of the NRK Radio Network.
WBear2GCR
Member

Offline Offline

Posts: 4042


Brrrr- it's cold in the shack! Fire up the BIG RIG


WWW
« Reply #4 on: March 17, 2011, 10:28:59 AM »


Nice BENDIX transistors...

Probably works fine... Cheesy


                          _-_-bear
Logged

_-_- bear WB2GCR                   http://www.bearlabs.com
KM1H
Contributing
Member
*
Offline Offline

Posts: 3519



« Reply #5 on: March 17, 2011, 01:24:42 PM »

It looks like a nice HB 12VDC to several useable output voltages using that GE 380 cps transformer. That will sure cut down on the filter cap requirements.
Logged
WU2D
Contributing
Member
*
Offline Offline

Posts: 1770


CW is just a narrower version of AM


« Reply #6 on: March 17, 2011, 08:29:56 PM »

I looked at the soldering and components and am convinced that it is not homebrew. It is commercial.
Logged

These are the good old days of AM
Opcom
Patrick J. / KD5OEI
Contributing
Member
*
Offline Offline

Posts: 7780



WWW
« Reply #7 on: March 17, 2011, 10:32:00 PM »

The exposed wires made me think otherwise but OK. Did you get it fired up yet?
Logged

Radio Candelstein - Flagship Station of the NRK Radio Network.
Pages: [1]   Go Up
  Print  
 
Jump to:  

AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
 AMfone 2001-2015
Powered by SMF 1.1.21 | SMF © 2015, Simple Machines
Page created in 0.069 seconds with 20 queries.