i agree re BFO..any thoughts on how to confirm which one is the culprit? was thinking a heat source ..ie hair dryer ...or small light bulb,directed independently at each might reveal some interesting results.. Larry WA0QHF
Sent from my iPhone On Jan 5, 2012, at 2:59 PM, Garey Barrell <k4...@mindspring.com> wrote: > Larry - > > That is interesting.... I've never experienced it, as my shack has always > been air conditioned. The PTO coil is pretty well sealed, and I wouldn't > expect it to be susceptible to humidity. The only other sources would be the > BAND oscillator, crystal controlled with a lacquered transformer, the 3rd > Mixer LO, also crystal controlled, and the BFO. The BFO is just an 'IF Can' > style coil, and would be the most likely suspect. > > Would be interesting to see which of these oscillators is actually the one(s) > moving.!! > > 73, Garey - K4OAH > Glen Allen, VA > > Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line > and TR-4/C Service Supplement CDs > <www.k4oah.com> > > > Larry Mccabe wrote: >> i've noticed some interesting drift characteristics on my r4c. i live in >> florida.. shack in the garage.. during the summer months , with 80-90 deg >> temps and high humidity, the r4c drifts approx 50 hz per hour. during the >> winter with 50-60 deg temps and reduced humidity the drift is reduced to 10 >> hz per hour . in both cases these measurements were observed after a lengthy >> warm-up period using a digital display counter. i have no internal fan or >> aux cooling in the radio. only significant change in the vacinity of the pto >> is the sherwood audio amp mod . temp and humidity obviously a significant >> factor in dealing with drift. i know this is no big revelation.. thought the >> differences were interesting though. >> Larry WA0QHF >> >> Sent from my iPhone >> >> _______________________________________________ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
