I've had the ovens apart to replace a dead 3N128 in one of my 1250As. What you are adjusting is a trimmer cap in the oscillator circuit, and if too much pressure is applied trying to engage the slot in the trimmer, it is easy to bend the trimmer off at an angle where you will never be able to find the slot again. The Austron supplied tool is a dielectric rod of 18 cm length, 3 mm in diameter, with a 3 mm steel flat blade 2 mm in length protruding from the end of the rod. The blade easily fits into the trimmer's slot, but as was mentioned in the previous post, some of the trimmers are sticky, and require some torque to get them moving. I measured the inner oven's temperature as 63 C which is the temperature that trimmer lives at.
-Doug W6DSR -----Original Message----- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of John Reed Sent: Saturday, February 21, 2015 5:56 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Austron 1250A Tuning tool I adjusted my 1250A using a 1/8" brass rod that I got from the hardware store. I filed down the end to make it into a screwdriver. This worked fine. I could tell when the tip was engaged with the screw in the oscillator by feeling it fall into place and then I could make the adjustment. The brass didn't have any effect on the frequency. When I removed the tool the frequency didn't change. A metallic tool is needed since the adjustment screw needs some torque to make it turn. -----Original Message----- From: Ole Petter Ronningen Sent: Saturday, February 21, 2015 1:07 AM To: time-nuts@febo.com Subject: [time-nuts] Austron 1250A Tuning tool Hello My 1250A has drifted outside the range of the front panel control, so the coarse adjust needs some fiddling. The manual makes mention of a special tool to be used for this. I don't have the tool, the closest I can get is a 10" bamboo stick that I cunningly liberated from my wifes sushimaking mat! I wondered if anyone else on the list has this tool, and can send me a description/photo of the tip? I tried widdling the tip of my stick to various shapes, but not knowing what it is supposed to mate with, it is a bit frustrating.. Thank you all _______________________________________________ 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. _______________________________________________ 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.
