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Radio antenna selector switch mystery signal boost
#4

Scott,


Quote:...all my sets do not have a dedicated ground rod.

...on the GE, i experimented 7 different ways to Sunday. I even removed the loop, kept the ground end on the set and connected the other end to my outdoor long wire,,, its result was nothing but a bunch of humming.

An external antenna must be considered a "complete circuit". RF intercepted and returning to Earth. and vice-versa, flowing back and forth at "all frequencies". The current antenna cannot develop this "flow" except via stray or deliberate coupling via internal coupling capacitors within certain radios.

I can only assume the G-E is in a poor reception area as its internal loop is in play. Some of my text asks for the creation of an external loop for the G-E. The purpose of which is to couple the "greater strength" of the external antenna to the G-E's internal loop. There must be that Earth ground to "close the circuit" for the external loop to be excited with RF.

It is this same RF flow via the antenna and Earth (ground) that must be established for each of the sets taking account of how the RF is "flowing" in the respective antenna input circuit of each radio.

Some radios couple ground to establish the Earth antenna current flow via the AC line. That works but must be considered when an external Earth connection is made. Returning RF to Earth via the home electrical system often introduces noise and in some instance becomes a significant part of the antenna system generally with poor results. Modern home electronic equipment will use switching power supplies as well as discharge lighting, etc.

Noise from home electrical equipment is often not recognized as a primary contributor of poor receiver sensitivity. The noise creates an AVC signal just as effective at reducing the gain of the receiver as much as the desired programming.

A majority of noise enters the radio via the antenna, but also via the power cord, especially when the radios design uses the power cord as the RF return.

Once a suitable SHORT ground to Earth is installed then work from there discovering the best method to couple the radios antenna to the switch.

As for the sudden failure of the G-E. If the power cord has not been recently replaced, check where the cord exits the molded power plug. When the radio was in service, the power plug may have used in an outlet where during the "daily" room cleaning the cord was moved back & forth. That motion will eventually breakdown the strands of the wire causing an intermittent...

GL

Chas

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


Messages In This Thread
RE: Radio antenna selector switch mystery signal boost - by Chas - 09-24-2018, 08:43 AM



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