Hi all, [Sending this to the list instead of directly to Gary and Peter, the usual suspects, in case the results are generally useful.] In the process of buttoning up my repaired (mostly) Omni VI+, I
Hi Gary, Good tip on the filter bypass. If not too much trouble, I'd be most grateful if you measured the IF filter board "gain". While you are in there, it would also be very helpful to check and re
Hi Pete, Hmm - already checked the LO level coming in to the BPF board on connector 26 during an earlier investigation. Depending on band, I got a sine wave with +/- 0.5 to 1.35V using a 1 Mohm input
Hi Pete, Scratch that - forgot a square. The range of LO drive is actually +7 dBm to +15 dBm. The +7 dBm is in fact on 40 meters where I was testing - definitely low. Maybe that increases the convers
Hi Pete, Got a few minutes today. Discovery #1: the post-mixer JFET amplifiers were all shut off because they were not receiving any DC. Culprit was a bad inductor (not a soldering problem) - L39, a
Hi all, Every Omni VI I've picked up over the past few years, all five of them, Speaking as a person still in the middle of several very puzzling problems on a VI+ (which have been detailed here and
Hi Pete, Lunchtimes are useful for making incremental progress. I've examined LO drive into a 50 ohm load on the cable labeled 26 which leads to the BPF, where radio is set in "CW" mode. Using an Agi
Hi all, The saga of the deaf Omni VI+ continues. As a reminder, the rig had a repair to the post-mixer amplifier on the BPF/front end board and then I found it was deaf on RX for four low bands (160
Hi all, (I hope someone else someday can make use of this VI+ debugging information..) I'm still troubleshooting my VI+, which you can follow by searching the archive. In particular, I'm still figuri
Hi again, [Forgot to mention: I jumpered across this filter (from D41 to D36) with a 0.01uF capacitor and the receiver came to life on 40 and 30 meters, so this latest problem is definitely in the ba
Hi again, I was hoping to avoid the words "coil rewind" but I guess you're right. Time to break out the magnet wire. Rats. By the way, for posterity, the bandpass filter topology is interesting and b
Hi all, Will KD4FOV and I have been removing what hair we have left trying to troubleshoot a XO/LO board problem for the VI+ under surgery. (See the archives for more detail.) The difficulty has been
Hi Malcolm, I have an Omni VI+ and a good cellphone camera. Please contact me off list and I will find the diodes on the board and send you a marked photo. I have the rig open for repairs so it will
Hi Stuart, Also in play is the diode capacitance (related to switching speed of course) and the forward resistance. The BA482 high speed diodes specified on the BPF board have only 1-2 pF capacitance
Hi Doug, I have a Omni VI+ that needs some repair (a couple unstable LOs) so I had the same question as you did, assuming I can find the problem. I'll be interested to follow the answers. 73 Phil W1P
Hello, I have put the installation instructions at the link below in PDF. Very sorry for the terrible quality but these were done on a phone in 15 seconds (not near a scanner). If you look at the IF/