Adriano, If I understand correctly, you hear practically nothing from other stations, but you can hear your own transmitter (very weak), but shifting either receiver or transmitter VFO does not change what you hear. To me that suggests the the signal you are hearing is not going (properly) through the VFO mixer stage. You might have lost your VFO or 1st mixer tube or some other component in that area.
The first thing I would do is substitute that mixer tube if I had one. You could tap/wiggle that tube with the receiver on to see if you detect any intermittent connections. Give the tube pins a good close inspection for corrosion. They might benefit from a cleaning of the pins on that tube with wire brush or some gentle scraping with a knife, or dental scrapper, or some other technique. You could apply some Deoxit to the cleaned pins with a Q-tip type applicator. If you have a tube pin straightener, use it on that tube, or visually (carefully) straighten the pins if they are bent, but be gentle and sparing so as not to break the tube. I would measure voltages/resistances around the 1st mixer and compare to the manual, but you said you are not a technician, so don’t do this if you are not comfortable with the procedure. To establish weather or not the VFO is working, you could try to hear it with another receiver. Both receiver and transmitter VFOs are 4.955-5.455 Mhz. Try to hear the transmitter first. If you can hear that one, the same technique should work for the receiver. I have an R-4A, and am speaking from radio theory in general rather than from any specific experience with a C-line receiver. Good luck, KB8BKU Darryl On Feb 5, 2014, at 9:24 PM, Adriano <svi...@blably.com> wrote: > > > Hello everyone > > This's a real sad day for me as my beloved R-4C is dead. It was perfectly > working yesterday night while i was listening a local net on 80m but today i > can't listen anything. > So i checked if tube heaters glow...and they do. I've cleaned the "Mode" > switch with Deoxid D5 ...No results. The audio is VERY weak even if the > volume pot is full clockwise. > I can hear myself while transmitting with a transceiver ( plugged onto a > dummy load ) , the S meter needle stand on S 9 even if the transceiver "sit" > on the receiver . > I can hear myself even if I turn the PTO knob...same as if i turn the > transceiver Vfo. I don't hear myself f i switch on a diff band or a Crystal > position. > There's IS different tonality while operating the passband tuning. > > Also, while No signal at all, the S meter needle stand on VERY fast LEFT . > This both on "On" position or Ext Mute. > > I checked if any tube bad connection on theyr sockets by tapping one tube at > once with a tiny wood stick ( I did it VERY GENTLY ). > I was listening through my headset and the "tap" sound came on my ears only > with V5 tube, wich is a 6BA6 and it's the last If amplifier. > > Not a technician here...definately not. Also i know that my english is VERY > poor and , for that, i'm sorry. > > Anyway...as my R4-C is my TOP receiver and always i get Lotsa fun while using > it....is there someone who can please tell me where to check to get a chance > to repair it ? > I have other receivers but... > > Oh right, my R-4C doesn't have ANY of Sherwood modifications. > > Thanks in advance > > de Adrian, iz3svi > _______________________________________________ > Drakelist mailing list > Drakelist@zerobeat.net > http://mailman.zerobeat.net/mailman/listinfo/drakelist
_______________________________________________ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
