I picked up a Manson RD-146 a couple of years ago to play with. After getting that out of my system, it sits on the shelf awaiting a new home. It's interesting that the manual says they are a subsidiary of Hallicrafters.
73, Dick, W1KSZ -----Original Message----- >From: David Olean K1WHS <k1...@metrocast.net> >Sent: Mar 17, 2011 12:34 PM >To: time-nuts@febo.com >Subject: [time-nuts] HP106B crystal oscillator > > >I have a vintage HP 106B crystal oscillator. It has been sitting around for a >few years and I just recently found a schematic for it. It was enough so I >could dig in and check things out. The first thing I tried when I got it was >to run the unit on external power as the internal PS seemed to be hosed. The >oscillator fired up and stabilized at something very close to 5 MHz so I >suspected that the ovens were working properly. There it sat for a few years >until I found a schematic so I could fix the power supply. > The first chore was to remove the old and defunct NiCd battery pack and I > discovered that it was causing the power supply to be NG. I ordered some new > D Cell NiCDs (20 in fact) and rebuilt the NiCd pack. Once the shorted cells > were removed the supply started working again and all voltages are within > range. I was thrilled to get it working. With the new cells in place, they > trickle charge and will run the unit for many hours during power failures and > moves. > This HP106B was in the cal lab at Sanders Associates at Nashua, NH. It was > apparently scrapped around 2006, and ended up out in the weather in a metal > scrap yard in Northwood, NH where my brother found it and then he gave it to > me. He knew I liked precision things so figured I would like the HP106B. > (Good thinking!) At present there are only two issues with the unit. The > meter face is cracked and partially broken. But what do you expect from > getting thrown in a dump anyway? The fine tuning gear train has a problem and > seems to be binding up with only a limited range of travel. I hope I can find > a new meter cover. The movement is perfectly fine. > Now that it is working, I plugged it in and it has been running for about > 2 weeks. Initial results are encouraging. I set freq with the coarse > adjustment and so far it seems to be quite stable when compared to a Z3801. > My initial setting produced results within 4 parts in 10-9 of the Z3801, and > that has remained pretty much constant these last two weeks. (I compare > frequencies on 10,368 MHz to see how close the counters are) To get the > initial setting, I used an oscilloscope to freeze the two traces (Z3801 & > HP106B) I was not too careful but I am encouraged that the drift over 2 weeks > seems to be non existent as far as I can see. Eventually, I will get up my > nerve and attack the fine tuning gear train. First I need to run things for a > few months and try to get a feel for how well the oscillator is working. Then > I have to figure out the best way to calibrate it! > I also have a pair of old tube type Manson proportional oven oscillators. > Part #s are RD-140 and RD-146. They are 1 MHz units. I have one of those > running but suspect that they are not very good performers. I just turned it > on, and after a few days still see fluctuations of +/- 0.2 Hz. Maybe I need > to DC regulate the filament of the oscillator tube? That is an obvious source > of error. Possibly I could run it on a constant voltage transformer to test > my theory. These old klunker oscillators are fun. So much labor went into > their construction etc, that I feel it is a sacrilege to ignominiously heave > them into the dumpster. They deserve better! Has anyone else ever seen these > Manson oscillators? > >Dave Olean K1WHS > >_______________________________________________ >time-nuts mailing list -- time-nuts@febo.com >To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
