[Heath] AR-3 issues.

[Kenneth G. Gordon]

I have finally been able to start re-building my first Novice station, an AR-3 and a DX-35. 

I have the transmitter situation well in hand, and am now beginning the receiver end.

Over the past several years, I (somehow) aquired three AR-3s in various states of 
completion and condition.

Yesterday and last night, I pulled the most complete one out of the pile and began to do 
some work with it.

The first thing I did, after checking the power supply and finding it "adequate", was to align 
the receiver. 

That went reasonably well, and the dial accuracy is now about as good as it ever was, I 
would guess. 

2.5, 5 and 10 MHz WWV appear very close to where they should be on the dial, and the BC 
band accuracy is also very close. Inputting a signal at 25 MHz also shows up very close on 
the dial, although on band "D", the 10 MHz end seems almost dead. I'll work on that later.

My main issue right now is that when I turn the BFO on, I get a HUGE amount of hum out of 
the speaker and nothing much else. With the BFO off, there is a bit of hum, but it is not 
particularly noticable.

At this point, I suspect either the 12AV6, or something still not quite right in the power 
supply. I will make a closer examination of the power supply, and will replace the 12AV6 
asap.

So, I am wondering if anyone else here has run into a similar situation with the AR-3 and 
what you may have done about it?

As I suspected, the AR-3 is a VERY marginal "communications" receiver. As I may have 
remarked here some time ago, I cannot now see how we ever used such receivers, and 
even worse ones like my original Hallicrafters S-41G, to actually communicate with when we 
were young and didn't know any better. I was first licensed as a Novice in 1956 when I was 
still 13 years old.

I am also thinking of "re-kitting" the other two AR-3s I have into at least one good one, just 
to make sure what I have is built properly.

Might anyone have one of those small, transparent "dials" which were originally included as 
part of the bandspread capacitor that they might part with? Of the three receivers I have, 
only one still has that: the one I worked on last night.

BTW, replacing the 12BE6 with a new 12CS6 makes a very noticable improvement in the 
receiver's sensitivity on the higher bands, and the receiver also appears to be more stable.

vy 73 for now,

Ken W7EKB