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THE AM BULLETIN BOARD => Technical Forum => Topic started by: wa2tak on June 23, 2023, 02:34:46 PM



Title: DX 60 L1 / 40M
Post by: wa2tak on June 23, 2023, 02:34:46 PM
Hope no one is bothered by me taking up so much 'bandwidth' on this forum.

What the heck is the purpose of L1 / 40 meters?

I see only scant mention "check" and "peak" watching driver bias...

1. how is it FIRST set?
2. what 'peak' to look for and what settings to do this?
3. where / how to look?


Title: Re: DX 60 L1 / 40M
Post by: DMOD on June 23, 2023, 11:45:19 PM
Hope no one is bothered by me taking up so much 'bandwidth' on this forum.

What the heck is the purpose of L1 / 40 meters?

I see only scant mention "check" and "peak" watching driver bias...

1. how is it FIRST set?
2. what 'peak' to look for and what settings to do this?
3. where / how to look?


L1's inductance parallel resonates with tube and parasitic capacitances for enhanced signal levels from 40m and up.

Set BSW for 40 meters. Measure voltage across R6. Use a 7.295 Mhz crystal or VFO. Key transmitter and adjust 40 meter coil screw for max neg. voltage (bias) across R6.

Phil - AC0OB

AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands