[Heath] AR-3 issues.

[Guy Giacopuzzi]

Couple things here....
     Think about simply changing out /all/ of the tubes, if just on 
general principles...you might find it makes quite a difference in terms 
of performance. I've been learning the hard way from an SB-101 I've been 
restoring that a tube tester doesn't detect mediocre tubes that should 
be replaced.   Also, on general principles, replace /all/ of the 
electrolytics with newer units.  This might get rid of your hum..
     Secondly, I used a newer generation Heathkit as my first novice 
receiver--the GR-64.  It's sensitivity was amazing, but of course, it's 
selectivity was as wide as a barn door when used less the matching 
Q-multiplier.    But I used a technique my elmer taught me--get 
selective to the /tone/ of CW signals.  Now while the 64' only had four 
tubes, I think it will outperform any AR-3, at least in my experience.
      Of course, if you decide to "re-kit" the unit or another, test 
each resistor and cap prior to installation.  I'm currently rebuilding 
(from a re-kit) an AR-3 at my second home--been working on it on and off 
when it snows too hard at my 2nd home in Mammoth Lakes..and as a result, 
it's still not finished after about 10 years....
Guy

On 4/18/2016 9:24 AM, Kenneth G. Gordon wrote:
> 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
> _______________________________________________
> Heath mailing list
> Heath at puck.nether.net
> https://puck.nether.net/mailman/listinfo/heath
>

-- 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://puck.nether.net/pipermail/heath/attachments/20160418/72f1d44e/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 2012email_signature.jpg
Type: image/jpeg
Size: 117949 bytes
Desc: not available
URL: <https://puck.nether.net/pipermail/heath/attachments/20160418/72f1d44e/attachment-0001.jpg>