[Heathkit] sure will appreciate help on getting straightened out onSB-221

[Donald Spoon]

I have tried both the Harback "Softkey" and the Ameritron ARB-704 in two 
different amplifiers.   Both are excellent and work in a similar manner, 
but I think I prefer the Ameritron solution.  It is entirely external 
and doesn't require any changes to the internal wiring of the 
Amplifier.  Additionally, it can move with you when you change to a 
different Amplifier.  It is the "Swiss Army Knife" of the keying 
relays.  About the only "problem" is obtaining or constructing the 
proper interconnection cables, and Ameritron gives you a selection to 
choose from...   With the Harbach, you have to construct the board, then 
install it inside the Amplifier.  The directions are great and easy to 
do, but for an old Geezer like me, this is just another opportunity to 
make a mistake!

One definite advantage over the "buffer relay" solution you originally 
described is the elimination of another relay in the keying chain.  
Sometimes the additional delay from this "extra" relay will cause 
Sequencing problems to the Transceiver, and "may" cause a short period 
of very high SWR during changeover.  It can interfere with break-in 
keying for CW and many of the auto-tuners in modern tranceivers can be 
fooled by this transient causing an auto-tune condition if you have it 
switched on.    The electronic switches, like the Harbach Softkey and 
the Ameriton ARB-704 significantly reduce thin insertion delay.  The 
electronic switches are MUCH quieter too.... no ADDITIONAL  relay chatter!

Cheers,
-Don Spoon-
K0APK


On 2/17/2013 11:57 AM, john wrote:
> There's lots of choices, regardless of whether you want to build or to 
> buy.
>
> I have several AmpKeyers from the Heathkit shop, but I can't find 
> their website. Ameritron makes a similar unit:
>
> http://www.ameritron.com/Product.php?productid=ARB-704
>
> That will solve your issue. Easy to hook up  and to use.
>
> John k5mo
>