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Title: VIKING2 OUTPUT LOW, THEN CREEPING UP... Post by: ve6pg on November 23, 2010, 06:37:08 PM ..hi from tim...my viking2 when i throw the plate switch, has abt 50 watts output, low grid drive, then creeps up to where it should be...this takes about 30-40 seconds....then all is fine...plate current, drive levels etc...
...any ideas?.. tnx.. ..sk.. Title: Re: VIKING2 OUTPUT LOW, THEN CREEPING UP... Post by: n2ry on November 23, 2010, 07:11:12 PM check both 5r4gy's, same thing happened to my dx-100b, i had a non working 5r4gy, filament went and it was stone cold, took the one left a bit to get up to speed
rich n2ry Title: Re: VIKING2 OUTPUT LOW, THEN CREEPING UP... Post by: KA0HCP on November 23, 2010, 07:15:00 PM It's a sad tale we often hear this time of year.......'slow electricity'.
Try leaving a circuit cracked open so the electrons can flow, and open the door on the circuit breaker panel. Good luck! :) Title: Re: VIKING2 OUTPUT LOW, THEN CREEPING UP... Post by: WD5JKO on November 23, 2010, 07:55:38 PM My bet might be one of the following: soft 6146's soft 6AQ5 RF driver tube LV B+ problem If the above three items were OK, and the HV B+ was sagging, then the 6146 grid drive would be plentiful from the start. Also try it with a crystal if using a VFO. My 2 cents, Jim Title: Re: VIKING2 OUTPUT LOW, THEN CREEPING UP... Post by: WQ9E on November 23, 2010, 08:53:52 PM I would add one thing to Jim's excellent list: check the parallel mica caps that couple the driver to the final grid. These are prone to failure.
Title: Re: VIKING2 OUTPUT LOW, THEN CREEPING UP... Post by: WA1GFZ on November 23, 2010, 10:24:09 PM Check the 18 K resistor in the VFO. Last one I did measured 40K and still worked.
Title: Re: VIKING2 OUTPUT LOW, THEN CREEPING UP... Post by: W1AEX on November 24, 2010, 02:18:36 PM Check the 18 K resistor in the VFO. Last one I did measured 40K and still worked. Yup, when my Viker had wandering grid drive last winter, it turned out to be the 18k Chernobyl resistor, which actually crumbled when I removed it to install its much huskier replacement. Title: Re: VIKING2 OUTPUT LOW, THEN CREEPING UP... Post by: w1vtp on November 24, 2010, 08:41:49 PM Check the 18 K resistor in the VFO. Last one I did measured 40K and still worked. Yup, when my Viker had wandering grid drive last winter, it turned out to be the 18k Chernobyl resistor, which actually crumbled when I removed it to install its much huskier replacement. Could that not be checked by subbing a Xtal and see if grid drive comes back up? That would half split the problem VFO or VIKER |