GAREY - K4OAH <[EMAIL PROTECTED]> made an utterance to the drakelist gang ---------------------------------------------------------------------- Bent -
Boy the internet is slow today. Your message just showed up here! Anyway, what you are seeing is normal. For tune-up and CW, the Carrier Osc frequency is shifted to within the LSB filter passband, and the Balanced Modulator is unbalanced. The resultant signal passes through the filter with minimal loss, and then on to the Driver and Final stages. So the TR-4/C must be in the X-CW filter position for CW or TUNE modes. This is different than in the R-4/T-4 series. The T-4X converts the Mic Amp to an audio oscillator in TUNE mode, and this audio signal is fed through just like whistling into the microphone in SSB would be. So _EITHER_ filter can be used for TUNE mode in these transmitters. For CW mode though, the Carrier Osc frequency is shifted to within the LSB-X filter passband just like in the TR-4 which is why the switch MUST be in the LSB-X position. So. If you TUNE up in the X-CW MODE, then switch to the RED sideband and then whistle into the mic, you will get plate current. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line & TR-4/C Service Supplement CDs <www.k4oah.com> Bent wrote: > Hello > > I need some help for my TR-4C which give me some trouble. > Hopefully someone are able to give me some useful ideas. > > The receiver seems to be fully OK on all bands. > But something is wrong on the transmitter side. > > I have added a table which show what happend if I try to tune UP on the > different bands. > > When I turn the XMTR GAIN CW, and Mode Switch in X-CW, according to > Instruction Manual for tune up, > following happend: > > Band Lower sideband Upper sideband > > 80 Draw no current OK > 40 OK Draw no current > 20 Draw no current OK > 15 OK Draw no current > 10 OK Draw no current > > All the voltages from the AC-4 are OK. > Bias current on all bands is OK. > > Why will the transmitter not draw current in the red marked areas. > > Thanks in advance. > > 73 > Bent > OZ5ZD ---------------------------------------------------------------------- Submissions: [email protected] Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net ----------------------------------------------------------------------
