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Radio antenna selector switch mystery signal boost
#7

Quote:Scott:  on the GE set,, relocate a newly fabricated and calibrateable design loop antenna outside so it can couple with my long wire.
**this must mean i need to omit the original loop antenna, save it back.,,, or do you mean parallel in another?
The G-E radio stands unmodified. Calibrated? No way just a few turns of wire as big an area as the loop built into the back of the radio. Even if there is a ferrite loopstick. The new coil and the existing loop in the radio will creat an RF transformer with no electrical connection to the radio. For this loop transformer to work it must have the short, direct ground to Earth.

Quote:--The GE is back up now, i was tinkering / experimenting on the minerva set cause i cant seem to leave well enough alone. I unplugged the 6' long 20position power strip i have dedicated to the garage sets and simply forgot to plug the strip back in. I was trying to isolate out where this minor 30 or so volts ac was coming from on the skeleton frame that holds the isolated chassis. Also i was tinkering around with an idea i had about a simple S meter for the minerva.
 The"30 volts AC" is leakage, it can be coming from any radio that has line bypass capacitors or a transformer powered radio with a leaking primary winding. As long as it is less than a few ma it is a non-issue.

The AVC can be monitored with a battery powered DVM on a low voltage scale or the IF or RF plate current monitored. Both schemes will show relative changes in signal level. An accurate "S" meter is a defined circuit that is directly related to the sensitivity of the receiver, generally reference 600 ohms.. I have never modified a receiver for an "S" meter although I have radios with "S" meters OEM...

GL

Pliny the younger
“nihil novum nihil varium nihil quod non semel spectasse sufficiat”


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RE: Radio antenna selector switch mystery signal boost - by Chas - 09-24-2018, 02:17 PM



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