Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Closed
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

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”


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



Users browsing this thread:
[-]
Recent Posts
philcorepairbench.com - shadow-meter
Thanks Ron.fenbach — 02:43 PM
Model 70 Cabinet Trim
Thank you, Gary. Before making my original post, I had clicked on "Steve Davis Cabinets" only to find that it...musar — 02:25 PM
philco predicta
Welcome to the Phorum, cgl18! I am not your resource for television repair, but lots of friendly help is available here...GarySP — 02:12 PM
Model 70 Cabinet Trim
Welcome to the Phorum, musar! You can send Steve Davis a private message (PM). The site is at the top of the Home page...GarySP — 02:09 PM
Model 70 Cabinet Trim
How do I contact him? The only contact information for him I could find when searching online was a telephone number th...musar — 10:38 AM
philco predicta
Hello, good afternoon, I would like to ask what the possible problem could be if I don't have an image on the screen. I ...cgl18 — 10:19 AM
Philco model 38 code 121 not receiving signal.
So one last question before I finish this radio. Regarding the speaker and output transformer. I salvaged the original o...Stormlord5500 — 09:31 AM
462ron
It’s on the bottom of the homepage of our Philcoradio.com homepage! Ron462ron — 07:20 AM
Model 70 Cabinet Trim
Steve might have some trim left. Not sure he is making anything.morzh — 06:12 AM
Model 70 Cabinet Trim
Hello musar, First all welcome to the forum and yes that is true that steve stopped making trim . Sincerely Richar...radiorich — 12:13 AM

[-]
Who's Online
There are currently 540 online users. [Complete List]
» 2 Member(s) | 538 Guest(s)
AvatarAvatar

>