[ARC5] command set bench psu

[J. Forster]

I fully understand Mike. I'd just not seen the unit in my WW II stuff info.

I've no interest in Type 12 stuff. BTW, it seems very few other people do
either- the stuff just goes begging. I mistakenly bought a big boxfull
about 30 years ago for about $5, and it's still sitting.

-John

==========



> They are indeed, John, but the WWII sets have about the same power
> requirements, so while the manual may not say ARA/274N or the like, it's
> a perfect supply for them. It's a neat little supply that doesn't take
> up much space on your bench, and is especially useful if about all you
> service are WWII aircraft receivers of various types.  It will power a
> BC-348 about as well as the command sets, for example.
>
> On 1/11/2013 5:38 PM, J. Forster wrote:
>> In looking at the pics, it seems they might be post-WWII and designed to
>> service the Type 12 stuff.
>> ===========
>>> Thanks for the good information!
>>>
>>> I got a couple of those; I never realized they were for the
>>> ARC-5/SCR-274N
>>> and later type receivers! I picked up 2 at a hamfest a long time ago
>>> for
>>> $25
>>> for both. I used them as general bench supplies, for the plate voltage.
>>> I
>>> never used the 24VDC output...
>>> Since they haven't been used for a while, it's time to dust them off
>>> and
>>> replace the rectifiers and mod them per Mike!
>>>
>>> 73, Meir WF2U
>>> Landrum, SC
>>>
>>> -----Original Message-----
>>> From: arc5-bounces at mailman.qth.net
>>> [mailto:arc5-bounces at mailman.qth.net]
>>> On
>>> Behalf Of Mike Hanz
>>> Sent: Friday, January 11, 2013 4:35 PM
>>> To: Darryl Sage
>>> Cc: ARC5 at mailman.qth.net
>>> Subject: Re: [ARC5] command set bench psu
>>>
>>> On 1/11/2013 2:52 PM, Darryl Sage wrote:
>>>> I saw a command set bench psu . i had to have it more mony than
>>>> brains.I
>>>> guess i can retire a few dynos  I have never seen one before are they
>>>> rare?
>>>> darryl    ve3cpo
>>> I'm assuming that you are referring to
>>> http://www.ebay.com/itm/ARC-5-Power-Supply-SCR-274N-Receiver-OEM-/1409024993
>>> 34
>>>
>>>
>>> I've had a few cycle through here.  I've used them for a while, then
>>> pass them on to someone who's wanting one.  They have some drawbacks,
>>> one of which you can see in the photos - the voltages tend to be on the
>>> high side rather than the low side as we are more and more trying to
>>> provide for our dwindling supply of command sets.  The selenium
>>> rectifier used for the low voltage supply should be replaced before it
>>> replaces you, and the HV bridge diodes could be replaced by four modern
>>> HV diodes.
>>>
>>> You can fix the voltages with a bucking transformer, but if I was
>>> keeping one, I'd put in a 6082 (24v filament) series regulator on a
>>> 3"x3" outboard chassis on the back, and design the circuit so that the
>>> HV switch steps started at maybe 50v and ended up around 220v. There
>>> are
>>> plenty of those circuits in the manuals.  Then it would be pretty
>>> useful.  It's a shame the nifty cable with the dynamotor connector was
>>> retained by the seller, but you can cobble one up fairly easily, if not
>>> as elegant looking.
>>>
>>> Congratulations on your purchase - I'm sure you'll enjoy using it!
>>>
>>> 73,
>>>    - Mike
>
>