[Milsurplus] WWII Portable Regens

[David Stinson]

Thanks, Mike.  Pretty little thing.

On 1/1/2024 9:22 PM, Mike Morrow wrote:
> Dave, BC-186 is the receiver for SCR-178 and-179.  If you search the Radionerds site for SCR-178 it will take you to a page with a pdf link to the last manual for SCR-178 including BC-186...TM 11-231 12/1941.
> 
> SCR-178 operated only between 2.4 and 3.7 MHz.  Its BC-187-* transmitter uses a type 10 MO and type 865 PA, neither inexpensive.  It's all very early 1930's technology.  :-)
> 
> Mike / KK5F
> -----Original Message-----
> From: David Stinson <arc5 at ix.netcom.com>
> Sent: Jan 1, 2024 11:54 AMERICA
> 
> Been occasionally tinkering with
> WWII Portable Regens.
> Have a U.S. BC-186,
> Japanese 94-5 and German Torn e.B.
> The -185 and 94-5 are working and
> the Torn is getting there.
> 
> Couple of questions:
> Did the other major combatants-
> U.K., USSR, France, Italy, China etc.
> have similar and widely-deployed
> portable regens?
> 
> The BC-186 has two plug-in coils.
> My is 2400 KC to 3700 KC. I don't
> have a complete manual for the 186.
> Were other coil sets deployed?
> 
> All the caps and resistors were good.
> Only thing needed was to trace the
> non-original connector and use a quarter-
> inch piece of heat-shrink to prevent a
> a short between a coil's trimmer cap and
> the coil case. Simple and nice-sounding.
> https://photos.app.goo.gl/q5nfg7kZ5azUdVo89
> 
> The 94-5 is a little more "fiddly." I got
> lucky and found a "parter" with a good
> Audio Output transformer. I have fantasies
> about finding a 94-5 transmitter for it.
> Anyone want to trade a clean, working RS-6
> station for a clean, complete 94-5 transmitter??
> https://photos.app.goo.gl/fBfLzzwjnSEj6byY8
> 
> The Torn e.B is still "in progress."
> Been trying to recover someone's failed
> attempt at re-tubing the thing- they made
> a big mess. Here is a photo of an "oddity."
> https://photos.app.goo.gl/HJ95Er71RF3BNUfMA
> 
> One of the tube stages has
> a wire-wound, adjustable resistor across
> it's filament, the "slider" connecting
> to a 2-Meg resistor which goes to the
> signal grid of the tube. It is missing
> in my set and the screw securing it is
> broken-off in the chassis.
> 
> This area is very cramped and finding the
> exact mini-Wire-Wound with tap seems unlikely.
> The filaments are 2VDC.
> This is a voltage divider directly across
> this tube's filament,
> so the most voltage at the tap possible is
> 2V, and give the photo in the manual
> I assume this is a way to deliver
> negative bias to the tube
> without needing a "C" battery.
> Maybe 1 V is all the bias it needs?
> 
> Given that 100 Ohms across 2 VDC is only
> dissipating .04 Watts, I'm thinking a
> small 100-ohm pot will sub until
> a suitable original surfaces.
> Any insights on this circuit?
> 
> TNX ES HPY NY OM DE Dave AB5S
> 
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