[GreenKeys] Dovetronw versus HAL ST9000

[Roy Norris]

Hi Bill,

Thanks for the very thorough discussion on the Dovetron vs HAL ST8000 
comparison.  I was just curious how the two compare.  I have two Hal 
ST-8000's here and am very happy with them.  But, I am always interested to 
hear if there is something better !

My experiences with the FM vs AM style of RTTY demodulator operation has 
been similar to yours.  I performed my initial test of the two approaches 
years ago using an Irv Hoff designed tube Mainline TTL.  I always got 
better results with hard limiting as you pointed out. I later saw the same 
results with your very fine ST-6000.  I must admit I have never tried the 
Dovetron for just that reason.

It seems like the ST-6000 and the Mainline TTL alla Irv Hoff had a lot of 
similarities in design concept (notwithstanding the fact that one used 
tubes and the other was all solid state).  Did Irv have any role in the 
early HAL designs?  Or did he base his designs on the HAL approach?

I used to work Irv daily on 20 meter RTTY.  We had an autostart frequency 
and a bunch of us had used Irv's early programs for the Heathkit H-8 to act 
as a frequency monitor and to start our machines up when it detected our 
calls (it would cause the transmitter to come on and send a brief 
reply).  I guess that evolved into the RTTY mailbox craze.

By the way, thanks to you and to HAL for all you have done to promote 
amateur RTTY over the years.  No other company has contributed more to our 
cause.

Best regards -- Roy, K4EEG