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Title: Valiant with no oscillation NEED HELP! Post by: KF4IZE on November 25, 2016, 10:14:55 PM I have a Valiant I that doesn't exhibit oscillation. I did note that the 0A2 does not exhibit filament in the VFO compartment. The 6AU6 VFO tube has filament. I replaced the suspect 0A2 with a known-good one and obtain the same result. Additionally, there is no oscillation with a crystal in either the C1 or C2 socket. All other tubes in the unit light up just fine. Any help with be greatly appreciated.
Title: Re: Valiant with no oscillation NEED HELP! Post by: KB2WIG on November 25, 2016, 10:39:40 PM The VFO coupler is easily broken. You may find the following 2b of interest, http://amfone.net/Amforum/index.php?topic=19248.0;wap2 klc Title: Re: Valiant with no oscillation NEED HELP! Post by: KA2DZT on November 26, 2016, 12:08:51 AM I have a Valiant I that doesn't exhibit oscillation. I did note that the 0A2 does not exhibit filament in the VFO compartment. The 6AU6 VFO tube has filament. I replaced the suspect 0A2 with a known-good one and obtain the same result. Additionally, there is no oscillation with a crystal in either the C1 or C2 socket. All other tubes in the unit light up just fine. Any help with be greatly appreciated. The OA2 does not have a filament. It will show a bluish glow when the voltage on it is high enough for it to draw current. If you don't see any glow, you may not have any B+ voltage. Title: Re: Valiant with no oscillation NEED HELP! Post by: KF4IZE on November 26, 2016, 08:51:06 PM Appreciate all the help. I discovered an open LV choke. Just so happens I have two Valiants in the shack, so I ripped out a good choke out of the scrap Valiant and installed it into my working Valiant. What a joy to see the purplish glow of an 0A2 VR! Just waiting on some electrolytic and orange drops to round out the restoration. Thanks again! AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
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