[Milsurplus] ARC-2

[Meir WF2U]

I've been using my completely stock (with the dynamotor) ARC-2 for several years, mainly on CW on the 80 m band. I solved the selectivity problem with an outboard dual active audio filter - for peaking and notching different frequencies simultaneously. This makes the radio quite usable on a crowded band. The autotune channels are convenient to set to my net frequencies. I've had another one for a while as well, with a terrible front panel, from which the paint was completely peeled off by exposure to desert sand (it's from the famous aircraft graveyard), but otherwise pristine inside, complete with the dynsmotor. Just picked up a third unit, which was somewhat hacked; the dynamotor missing and its mount removed from the radio by drilling out the rivets holding it on the chassis, the microphone transformer replaced with a tiny transformer which looks like came out of an old transistor radio. This one will be a front panel donor to the one with the bad panel, so I'll have 2
operational ones.
BTW, I have 2 original plugs for the rear connector. One is used with the ARC-2 and the other with the ARR-15 receiver. Now to find a third one...

73, 

Meir, WF2U
Landrym, SC

On April 15, 2015 2:11:37 PM EDT, Hue Miller <kargo_cult at msn.com> wrote:
>An idea suggested for the ARC-2 selectivity challenge was to make one
>IF
>stage regenerative via grid-plate capacitor. Maybe, i'm thinking, this
>ideawas advanced in Roy Pafenberg's  ( sp ? ) booklet, something
>like,"ARC-2, A Modern Transceiver in a WWII Package".  I wonder how
>well thisidea works out in reality. Regenerative IF stages i have never
>liked; theyare simply too peaky and difficult to gain-control. But an
>added Q-multcircuit, a 2-terminal one, is an idea i want eventually to
>try.Talking with Walt Hutchens years ago about the ARR-15, i mentioned
>regenerative IF stages for this receiver, but he said he felt the
>trackingof the variable IFs was not true enuff for this to work.
>However, thinkingabout it, i believe tracking not that big an issue, if
>you're not absolutely tied to the idea of perfectly accurate dial
>frequency readout. After all,you can compensate via the tuning knob. 
>Now on the ARC-2, the problemmay seem a little more challenging, in
>that you face tracking problems both with the osc and the
>simultaneously variable. However, i d
>on't think that's a game stopper: as long as the IF tracking is going
>off in thesame direction, i.e. not jumping up and down, i think you can
>still just use the tuning knob to find your signal, depending less on
>the actual frequency readout. So i think the regen IF, or better, the
>Q-mult, would be applicable here too. BTW, this 2-terminal Q-multidea
>also appears in one of RSGB Pat Hawker books, "Amateur RadioTechniques"
>i think it is, where it is applied to an IF stage and it usesa dual
>triode like 12AT7. I emphasize that this Q-mult, like a
>Franklinoscillator, uses the tuned circuit in the radio as its tuned
>circuit, and is a 2-terminal device, so it's easy to apply, and to DC
>controlremotely.Now to the ARC-2 design. Who has some thoughts about
>why so many RF stages to this thing? And why so many RF tuned
>circuitscompared to the IF tuned circuits, which really aren't that
>many -as seen in the -b r o a d - selectivity specs.Also - Pafenberg's
>booklet - i don't have - what di
> d his conversionconsist of ?-Hue Miller 		 	   		  
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