Re: FT-101ZD MK2 poor sensitivity ..
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Well, let me try... Green line shows marker signal flow, from the block diagram it is injected outside of the RF Unit board but before Q101. The marker circuit?is circled in red, the marker output in green: The marker comes out of Pin 2 on Jack 4 of the AF board.? From there it should go into the RX chain, but the manual doesn't specify.? It only says it goes through relay RL2, lamp fuse FH2, attenuator switch 2004 on the lever switch board, 9 MHz trap L2101 and C1207 on the Trimmer A unit, then transformer T1 to Pin 3 of the RF board.?? So, a dirty relay could cause your symptoms.? Have you tried cleaning RL2??? Lamp fuse FH2 is tested and good, so that's not the problem. ATT switch is another possible problem area, those switches are notorious for getting dirty. C1207 (circled in red) doesn't look like its variable, so less likely it's a problem: That leaves only 9 MHz trap L2101.? I'm not sure where that is, a 21 prefix should indicate the display board but that doesn't seem right.?? So, if you have cleaned out the ATT switch and the RL2 relay and still have the problem, that seems to only leave the fixed capacitor on the Trimmer A unit, the mystery 9 MHz trap wherever it is hiding, or something in the wiring harness between them all. Hope this helps, On Wed, Jan 12, 2022 at 5:23 PM <andrewhege33@...> wrote: Hello Chuck, |
Chuck, WS1L