[ARC5] Switching the dreaded B+ line

[Leslie Smith]

Hello Jim,

Your question was:  "Why not use the general scheme provided by that
excellent fellow, Dave Stinson, to put a "command" transmitter on the
air?"  Great question.

 Dave's notes are priceless, BUT his scheme assumes several things.  It
 assumes a control box (to switch the aerial (eg BC-422)  between a
 transmitter and receiver.  It assumes "your" transmitter is complete
 (sort-of) and that the relays etc are present.  Dave's scheme deals
 only with the transmitter, and not a transmitter-receiver pair.  I
 don't have an means of controlling ANY simple transmitter or receiver
 pair (such as a BC-442 or BC451), and I'll bet there are a lot of
 people in the same boat. 

I'm trying to devise a "general" scheme to get these "command" sets on
the air, and not just "command" sets.  More than that want to create a
set of notes that a 13 year old in New York or New Mexico can follow. 
Now, my friend, Ken Gordan (who I think has a typical command
transmitter) does NOT have a rack.  In Ken's BC-459 the two relays of
interest (K-53 etc) are missing.  I see MANY sets on eBay in this
condition.  (BTW - I'll advertise for Ken!  If anyone has a rack and
matching 12 pin connector, send it to him.  Ken will hate me for doing
this, but he'll be pleased to get the rack and connector!!)

Now I spoke to Ken about saving these sets.  He said, "LOTS of command
gear is going to land-fill NOW."   I will bet $1 to a con-man's wife
that for every "command" set you see on eBay 10 are going to the dump. 
How do we save these sets?  Answer:  Get them on the air, and that means
showing your 13 year old (in Maine or Montana) how to do that.  

Ken wants to get a basic "pair" on 40m, with a dyno and haul it round to
field days.  Get kids interested.  Isn't this how we all got started?
Any simple set (with just 3 tubes) that is working will generate a "wow"
if it looks "nice".  Once interest is generated ANY set that is old or
battered is valuable IF IT GETS A 13yo ON THE AIR.  (In Kansas or
Kentucky.)  You have a battered set?  Show a kid how to make it "nice". 
Teach that kid the value of "nice" and working with tools!  Make America
GREAT again!!

So - that point is settled.  These sets need to be ON THE AIR - whether
in Alaska or Alberta.   If I take Ken as my "typical" fellow - no
modulator, no BC-456, no control box, and I want to get a whole rig on
the air, how would I do this?

My answer:  I designed a circuit that will match anything to anything. 
Rice-box to command transmitter.  Command transmitter to command
receiver.  Regen receiver to command transmitter.  OK, I've made that
point, and I made a prototype of my circuit.

You can see it (circuit and card) in the files on Yahoo ARC-5radio
(group)  I called it TRL - transmitter, receiver logic, get it?


That's my answer to your question.  If a set has the relay - use it.  If
the set doesn't have a relay, then I want my circuit (and notes when I'm
finished) will show how to do that.   

More than that, I want to make the set/circuit "nice" and one complaint
that I hear often is that keying K-53 is noisy.  BUT, if a switching
circuit was put "further back" it would be very easy to add a time delay
to K-53 coil (and solve 2 problems at once.  For people, (like Ken) all
this is simple, but for the 13 year old kid in Arizona or Arkansas, he
needs a diagram that works without a rack or a relay.  

Anyway, I'm collecting info (and experiences) about getting these sets
on the air.  The most difficult part - finding connectors (generally)
and a connector (specifically) for the rear panel.  I'm working on that
too - Pomona pins and a resin plug body.  

As  your idea about for keeping these sets "original" - that's fine if
you have an original set.  I have a "nice" ARA receiver, and one "almost
nice" transmitter.  (Plus some junk).  Most people don't have a nice set
- so preserve what you have, make it look nice and put it on the air.

That's what I think (but more importantly) - that's what Ken thinks and
KEN IS RIGHT.  HA!

Les