389
Mudduck
Posts: 39 
|
Post by 389 on Dec 26, 2022 19:40:33 GMT -5
Any tricks to prevent lid proximity from effecting the vfo frequency?
73
Adrian
|
|
|
|
Post by 2600 on Dec 27, 2022 0:42:55 GMT -5
Ahh, leaving the lid open?
Seriously, the proximity of the grounded metal lid just creates parasitic capacitance in the VFO tank circuit. Tram didn't bother to shield it, and this would seem like a clumsy thing to retrofit in there. Just physics. The exposed VFO tank components form a parasitic capacitor to ground when the lid gets closer to them. The VFO frequency will drop as the top is lowered.
One reason a peek inside a ham transceiver usually reveals a metal enclosure surrounding the VFO circuit.
73
|
|
