[hpsdr] Hysteresis, and driving a TS-830.

[Jeff Cook]

Since receiving the Mercury module I've been thoroughly enjoying myself 
playing with my HPSDR transceiver. I've got it coupled up to HRD (Ham 
Radio Deluxe) using Virtual Com Ports and Virtual Audio Cables, the 
connection speed is 57,000 baud, however, there is a noticeable delay 
(hysteresis) effect apparent. There is approximately a one second delay 
in commands from HRD taking effect in the HPSDR transceiver, is there 
anything I can do about this?  I notice no delay whatsoever when using 
the above to control my FT-847, I'm assuming that the delay is due to my 
using four pieces of software (HRD, Virtual Com port, Virtual audio 
cable, and PowerSDR) in series. Is there anything I can do to eradicate 
or at least reduce the delay?

As you know, the output from the HPSDR transceiver is 500 mW and I've 
got this coupled to the signal grid of the driver valve of my old 
Kenwood TS-830S. The impedance mismatch must surely be phenomenal, the 
output impedance of the HPSDR is 50 ohms whereas the input impedance of 
the 12BY7A driver valve I would guess to be about 500 K ohms, 
fortunately this does not have quite the deleterious effect that one 
might expect, presumably because it is not necessary to deliver much in 
the way of power into the 12BY7A in order for it to work. However, I 
find that whereas the output of the TS-830S under its own steam is 100 
W, but when driven by HPSDR it is 60 W. Can any of you suggest an 
impedance matching circuit that will enable the HPSDR to successfully 
drive the TS-830S?

Google for once has not come up with the answer, but then perhaps I'm 
not asking the right question.

Brief Computer Specification.

2.13 gigahertz Intel Core 2 Duo
64 kilobyte primary memory cache
2048 kilobyte secondary memory cache
4096 MB Dimm Memory

Thank you.

Jeff Cook G0AFQ.