Rich, what are the values for C1-C4? I was just eyeing a 28VAC filament transformer and thinking about using one of those DC-DC boost devices, but this is much simpler.

Dave N9ZC 

On Wed, Apr 5, 2023, 10:31 PM Rich Post <kb8tad@gmail.com> wrote:

Since the original question was power supply.  Here's a simple method I have used, a 24 volt transformer for the original series filaments.  The transformer also feeds a voltage quadrupler with common ground.  The 200 volt electrolytic capacitors were recycled from a couple of computer power supplies.  If you want more than 134 volts, the circuit can be extended to a fifth cap. 

73 de Rich KB8TAD

On Wed, Apr 5, 2023 at 10:53 PM <hwhall@compuserve.com> wrote:

Here's a look at another way to do a recap. The terminal board work was accomplished by Canadian Aviation Electronics (CAE) in 1955.

Wayne

WB4OGM

-----Original Message-----
From: Mark K3MSB <mark.k3msb@gmail.com>
To: Robert P. Meadows <rpmeadow@bellsouth.net>
Cc: Dennis Monticelli <dennis.monticelli@gmail.com>; hwhall@compuserve.com; arc5@mailman.qth.net
Sent: Wed, Apr 5, 2023 4:52 am
Subject: Re: [ARC5] BC-453-B Power Supply

" Do the “RECAP”  correctly"

Using Tom Frobase's cap replacement kit is not the "correct" way to refurbish a receiver;  it is an alternate way.  

Tom's kits are very nice as I've looked at them before but on all the receivers I've recapped I've used just solder lugs or terminal strips.   I've never had any problems.

As Tom's video says, the only one that's going to know what's inside the radio is yourself, so what it looks like doesn't matter, and I agree with him.  In the decades I've been restoring radios, never once have I had someone come into my shack and ask to look under the chassis.   If you're a purist,  then you will certainly not want to use solder lugs, terminal strips, or Tom's kit as none of them are authentic -- you'll restuff the potted caps.   I never restuff the caps; I just save them in a bag with the radio's serial number on it so when I sell it (or croak...) and my radios go to the next person they'll have the option to repot.

Interestingly, Tom seems to make a contradictory statement later in the video.  He indicates that when using terminal strips etc there's no structural way to put the capacitors in the radio and it looks like crap.   

If you're going to use your radio in an airplane going through air combat maneuvering then I'd worry about a good structural way to mount the replacement capacitors.  Otherwise, solder lugs and terminal strips will be more than adequate.

I disagree with converting the filaments to 12V - that's just my opinion; YMMMV.   Just buy or build a 28V supply and build a B+ supply.  I used a HB HV supply for years then went over to an HP-23 that I picked up at hamfest;  the LV output on the HP-23 with a dropping resistor works great.

Don't get me wrong, I'm not bashing Tom's kits -- they are very nice.   If you have a supply of caps, solder lugs and terminal strips which a lot of us have, I would not pony up for the price of his cap replacement kit.   If you don't,  Tom's kits looka to be a good one stop shopping solution.

73 Mark K3MSB

On Tue, Apr 4, 2023 at 10:47 PM Robert P. Meadows <rpmeadow@bellsouth.net> wrote:

Do the “RECAP”  correctly, purchase Tom Frobase’s capacitor kit, believe it is kitparts or such.  Slick printed circuit boards that hold the capacitors and fit the existing holes from removing the beeswax filled leaky tubs.  Works well, and I do believe that is what Aircraft Radio would have done, had such been available.

R

 

From: arc5-bounces@mailman.qth.net <arc5-bounces@mailman.qth.net> On Behalf Of Dennis Monticelli
Sent: Tuesday, April 4, 2023 10:38 PM
To: hwhall@compuserve.com
Cc: arc5@mailman.qth.net
Subject: Re: [ARC5] BC-453-B Power Supply

 

If you elect to not restuff the cap pots, it is easy to re-cap the set. Install a solder lug using the threaded stud that mounts the pot.  That's your ground.  Then it's typically three small caps (most are 0.05) from the lug directly to the stiff wires you cut from the cap pot terminals.

 

Yes, lower voltage than 250V works fairly well.  My experience is to keep it at least 60V for decent gain and sure starting of the BFO.  The lower in voltage you go the more you're going to want to short out one of the R's in the screen voltage divider to keep the gain from decreasing too much.

 

FYI.  My 453B pulls only10mA at 60V with new caps.  I've run it off a stack of 9V batteries and they last a long time.

 

Dennis AE6C

 

On Tue, Apr 4, 2023 at 6:57 PM <hwhall@compuserve.com> wrote:

Those Command Set receivers had a B+ dynamotor that supplied 250v at 60 mA. Many people operate the sets on lower B+.  If these little round "flower pot" caps are the ones you're looking at, they aren't soldered shut.  The edges are bent over the mica insulators.  Most people either trash the old cap pots or carefully remove, cut them open, restuff & either glue or solder the cut edge.

Wayne

WB4OGM

-----Original Message-----
From: Glenn Little WB4UIV <glennmaillist@bellsouth.net>
To: arc5@mailman.qth.net
Sent: Tue, Apr 4, 2023 7:45 pm
Subject: [ARC5] BC-453-B Power Supply

I have a BC-453-B that has minimal hacks.
At a recent hamfest I found a ARN-30 solid state dynamotor replacement.
This power supply will properly mate with the receiver.
Should this supply power the receiver properly?
Some of the can capacitors along the side of the receiver are leaking.
It looks like these have a soldered on top.
Is it a lot of trouble to rebuild these capacitors?

Thanks
73
Glenn
WB4UIV

-- 

-----------------------------------------------------------------------

Glenn Little                ARRL Technical Specialist   QCWA  LM 28417

Amateur Callsign:  WB4UIV            wb4uiv@arrl.net    AMSAT LM 2178

QTH:  Goose Creek, SC USA (EM92xx)  USSVI, FRA, NRA-LM    ARRL TAPR

"It is not the class of license that the Amateur holds but the class

of the Amateur that holds the license"

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