[ARC5] 10-Meter 274N RX - The 20-27 RAT-1

[Kenneth G. Gordon]

On 9 Feb 2013 at 7:08, Mike Everette wrote:

> The 717A, I am pretty sure, is "an octal based 6AK5."
> 
> It's a good tube; but the 6AB7 might actually be a better choice. 
> Without looking up tube characteristics, I am also pretty sure that
> the 6AK5 is a sharp-cutoff-type which doesn't respond to AVC action as
> well as a remote-cutoff would.  The 717A is, I think, also
> sharp-cutoff.  The 6AB7 is remote-cutoff.

Makes sense...
 
> Now, I'm not saying that progress is unnecessary; far from it.... but
> note:
> 
> For those who are of the opinion that older, longer-lead tubes are
> inferior, consider receivers like the National HRO (original) with its
> 6C6 and 6D6 tubes, which remains one of the quietest and most
> sensitive of tube receivers.  Perhaps an even better example is the
> RCA AR-88, which is so hot even with old octal types that it can, and
> will, hear the world WELL with only a few feet of antenna.... even on
> ten meters.

Or even the RAL-7, which also used 6D6s and 41s, which I used for at least 
12 years and always heard everything that my much later SB-101 heard.
 
> Been there, done that, and have shirts with both National and RCA
> logos to prove it.  And my receivers are un-hacked; they run
> full-stock.  

Kewel. I've always wondered how well the AR-88 worked. Too bad there are 
so few of them around these days. I understand that most of them went to 
England during WWII. There is supposed to be a ship-load of them sunk 
somewhere off the Washington State coast too.

> Many receivers died horrible deaths back in the day on account of
> ill-advised "hacking" on the part of hams who followed the advice of
> ill-conceived articles in magazines like SeekU.... ripping out not
> only the first RF stage, but entire front ends in a quest for that
> extra tenth-of-a-microvolt, often resulting in a howling, squalling
> tangle of untameable feedback that caused the whole project to be
> shoved off the bench and kicked under the table -- or chucked into the
> dempsty-dumpsty.

Yes. I have such a horrendously hacked BC-779 in my possession. I have 
always wanted to do a thorough test of its characteristics and compare them 
to a stock '779.....which I also have.

Ken W7EKB