Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 27 Nov 2010 11:25:30 -0600
Low or no output on a band or bands can be dirty switch contacts. 10, 12, and 15 haven't had much use in the past few year. It might be a quarter drop of deoxit on each contact with some vigorous swi
The Omni VI uses diode switching for all of that. I don't think there is a single mechanical switch contact (besides the band select push button) involved with the band selection. If it indicates th
It is important to determine whether the rig is transmitting on the correct frequency when the power is low. That is why I asked for the SWR reading on the 20m antenna. A common problem with these ri
Ken, if I'm correct the output from the l.o. mixer , port 26, should be pretty much the same on all bands? I do have a good scope but do not have a good signal generator. I used to have all that qual
Thanks Phil, I was not aware of leaky diodes, I did check them with a meter and maybe I should just replace them? I would never have thought the diodes in the receiver front end could be the problem!
Look at the diodes associated with connector 14 on the BPF/Front end Schematic. There should only be voltage on one band at a time, measured on connector 14. Phil C. S4r. k4dpk -- Original Message --
Phil, thanks again, I may do it tomorrow or Monday. Wayne Look at the diodes associated with connector 14 on the BPF/Front end Schematic. There should only be voltage on one band at a time, measured
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 27 Nov 2010 18:18:42 -0600
Question is does it receive on those bands? The LO is as critical to receive as to transmit and its the same LO. Loosing two bands on transmit is indicative more of a low pass filter problem where th
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 27 Nov 2010 18:20:19 -0600
The same bandpass filters are used for receive and for transmit. But unless there's a reason for multiple failures (like lightning) they are individual for each band. 73, Jerry, K0CQ ________________
Author: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Date: Sat, 27 Nov 2010 18:18:51 -0600
Actually according to the 564 manual and the schematics in it, the low pass filters are switched with relays. The band pass filters (used for both transmit and receive) are diode switched and unique
Gerald, with bad band condx I'm not sure about the rx but always wondered if there was something wrong there. I mostly operate 80 and 40m but I'm kind of thinking about selling the rig and want it to