[1000mp] Fw: Loud clicks

George (K8GG) & Marijke Guerin gmguerin at voyager.net
Sat Jan 2 14:03:14 EST 2010


Here is some information from Larry, W8VVG, that is applicable to the FT-1000MP and the FT-1000D and to the K-3 by Elecraft.  I have paraphrased it slightly so it fits the 1000MP reflector aims.

Larry wrote:
Lately I have noticed loud clicks on the on the first dit of a transmission on a few stations. We just went through that same problem with W8UVZ and discovered that his TR relay was going bad on his Command Tech. amp.  After replacing the TR relay we discovered the rig was keying too fast for the amp (xmt delay) thus hot keying the amp. It also caused the first dit to be distorted or missing altogether. (Some of the older amps have slower open frame relays.)  BTW we found exact replacement relays at Digikey.  The clicks remained even after replacing the relay.

Here is what we discovered after replacing the amp TR relay. The amp TR relay operates at 20ms, the Yaesu FT-1000D operates at 12ms and the K3 default is 8ms.  The K3 was reprogrammed to 16ms and the problem went away, However the FT-1000D xmt delay cannot be changed.  I found a simple circuit to speed up the TR relay on the amp (see www.k6xx.com ) fast relay for details. This circuit brings the amp operating speed to approx 10ms without damaging the relay.  If you have an FT-1000D, this should cure the spike on the first dit or dah and should prevent any damage to your amp relay and or tubes.  The Yaesu FT-1000MP has a programmable xmt delay in the CW break in setting. Menu 7-4.  One can set it accordingly to avoid problems with a amplifier TR relay.
(If you have a K3 just go into the xmt setup menu and change the xmt delay to 16ms, or whatever is needed for your amplifier relay actuating speed).
73 es HNY Larry W8VVG

Subsequently, Paul, W9AC, warned that too much delay in a transceiver may also cause distortion of keying or clipping of the first CW character in a transmission.  One should check that after eliminating the hot-switch spike by adjusting the delay or adding the relay accelerator circuit to the relay closure line or both.

Good luck and Happy New Year,

George  K8GG

                  


More information about the 1000mp mailing list