[AMRadio] Schematic needed
I need a schematic for an early Johnson Ranger. I have the later schematic but it is some what different then the transmitter I'm working on. The differnce is in the keying circuits. The Orignal BAMA site shows that schematic being there, the mirrored site does not. The orignal site is down. Any help would be appreciated. Thanks K6KWQ Dick Amps by MORE POWER __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [AMRadio] Schematic needed
Dick, was this you: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItemitem=180478413464 if so congratulations, it is a nice looking one. 73 Rob K5UJ On Wed, Mar 17, 2010 at 5:23 PM, RICHARD GEORGE k6...@msn.com wrote: I need a schematic for an early Johnson Ranger. I have the later schematic but it is some what different then the transmitter I'm working on. The differnce is in the keying circuits. The Orignal BAMA site shows that schematic being there, the mirrored site does not. The orignal site is down. Any help would be appreciated. Thanks K6KWQ Dick Amps by MORE POWER __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
RE: [AMRadio] Schematic Needed
Charlie, Please send me the diagram, and I will send you back some food stamps. My address is: Jim candela 3305 Kissman Dr. Austin, Texas 78728 I got my Gonset G50 cleaned up and transmitting last week. The AM modulation is AWFUL looking on the scope, but that appears to be how those yahoo's designed it. Looks like some simple modifications will make it tolerable. A storm of clip leads, and R-C changes seemed to make it linear at up to +/- 90% modulation at 20 watts carrier output. In stock form it was linear to only +/- 30%, and limited to +50% at the same time as -85%. Pretty crappy. I added plate to grid RC on the 5881's ( 1meg - .033 uf 600v). This cleaned it up a lot, but I needed more peak power. I then lowered the cathode resistor to get more peak modulator power. The lower value cathode resistance only kicks in during transmit ( 350 ohm rcv, 190 ohm xmit). The modulator's tubes in parallel, class A Heising modulation seem to modulate up to +120% now at 22 watts RF output (100% at 25 watts), and I am limited to -85% due the Heising circuit limitations. Today I found a way to cool the modulators a little, and maintain nearly the same peak power. I put a 7K 5 watt WW resistor in series with the modulator screens. The screens are not bypassed, so this drops the screen voltage some, and is another source of negative feedback. Still plenty of gain from my D-104. The scope pattern looks real nice now, and shows perfect symmetry up to 80% modulation. The receiver is another story. It works, but has audio motor boating (when tuning in the 50.4 MHz spot (signal), and tunes like there is regeneration somewhere. I replaced all the P/S electrolytics earlier this week. The receiver might want to kick my butt for a while. I have a real nice FET preamp for 6 meters. I may hook that up someday once I know if this receiver is OK or not. I hooked the G50 to my 80 meter inverted V, and I can copy all kinds of stuff (some cordless phones) including some amateurs on SSB, and CW. The built in VFO spot function acts as a BFO. This is not the best, but kind of cool for now. I ordered a ku4ab 6 meter loop, and I just received a D-104 Mic element (crystal) last week from Omnitronics. I just might have a 6 meter station coming together. 50.4 Mhz AM is the goal. Something tells me that 6 meters AM will be one of those bands where most CQ's go unanswered... Thanks, Jim -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Sunday, June 29, 2003 9:00 PM To: amradio@mailman.qth.net Subject: Re: [AMRadio] Schematic Needed BTW Jim, forgot to ask in previous e-mail...what is the problem with your G-50 Modulation?? Surely you dont want more than 90%?? 73 again. K0NG. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Sunday, June 29, 2003 8:57 PM To: amradio@mailman.qth.net Subject: Re: [AMRadio] Schematic Needed Hello Jim: I cant scan a schematic for you but can copy mine and send it via post. Let me know if you have not received one yet. My modulation on the G-50 has been described as excellent using a D-104 microphone. The ones I have heard sound good too, but not many lows. The receiver sensitivity in mine is worse than I think it should be, even for its time. I think it was around 6 uV for only 6 dB S+N/N ratio. Have not worked on it lately. My dial drive slips also but hate to tear out the reduction drive (lazy). Good Luck es 73 DE Charlie, K0NG. Quoting Jim candela [EMAIL PROTECTED]: Hi Fellow AM'ers; I am restoring / modifying a Gonset G50 six meter transceiver. I have the schematic, and documentation from the Bama ftp sight. The schematic there is of poor quality, and reading component values is next to impossible. Does anyone have a quality print of this schematic? A good print scanned would do as would a 11 X 17 paper copy. I got the transmitter going pretty decent. The stock modulation really stinks, so instead of fixing it Gonset made it a selling feature. With only minor changes it is now approaching decent. I am having problems with the receiver, and the squelch circuit. This is where I really need a readable schematic. Anybody out there with G50 on the air experience? Regards, Jim candela WD5JKO ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
RE: [AMRadio] Schematic Needed
John, Thanks for the input. Yes I have heard of this method. It seems that Gonset makes a feature out of the Class A Heising modulator in that they encourage the modulator to be overdriven, and over modulation in either direction is impossible. They put a .005 uf capacitor across the Heising reactor to roll off the highs. Since it is single ended, the distortion products are dominated by even-order products whch gives it that sought after tube sound the audiophiles pay dearly for with a SE 300B making 8 watts at 5% THD for a mere $1500 per mono-block channel. I don't like that approach, and I would rather be clean linear right up to the overload point. I usually use some form of negative cycle attenuation (not loading) to keep the carrier power above zero though. See file I attached on NOS Yahoo user group under files, Super modulation, another mans approach. http://groups.yahoo.com/group/newoldstock/ It seems that with class A Heising modulation, the same thing is accomplished, only a little more abruptly. I don't want to over modulate, and chop up the carrier, but I would like to get the limiting (-) modulation from about -85% to -95%. Since the modulators (two 5881's in parallel) use cathode bias, I was thinking about making a change there. I could go fixed bias (I worry about stability), or put the cathode resistor from HV transformer CT to ground in effect making a fixed bias, and at the same time lowering the 6146 B+ by the I^2R drop of the Ct to ground resistor (seems tricky to get bias right between rcv xmit), or I could return the cathode resistor to a negative voltage like minus 50 to - 100 volts adjustable to in effect define the maximum (-) modulation percentage. Or I could do exactly as you suggested, and run a real nice 15 watt output. For now I will leave it alone. Thanks for the suggestion, Jim Candela WD5JKO PS Check out my QRO Central Electronics 20A files, and power supply schematic at the NOS Yahoo site. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of John Coleman Sent: Monday, June 30, 2003 8:17 AM To: amradio@mailman.qth.net Subject: RE: [AMRadio] Schematic Needed Hey Jim I remember Otis showing me a way to get 100+% Modulation from Hiesing the circuit. But it requires that you drop the output a little. He would place a resistor between the modulation choke and the final supply point. Then bypass it for audio with a large capacitor. This would couple lower the plate supply voltage to the final but would allow the same modulation voltage to appear on the final. I know it's a cheap fix, but you may not have thought of it and you have to be willing to lose 20% of the plate supply to the final to gain 20% modulation. John, WA5BXO -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jim candela Sent: Sunday, June 29, 2003 11:43 PM To: amradio@mailman.qth.net Subject: RE: [AMRadio] Schematic Needed Charlie, Please send me the diagram, and I will send you back some food stamps. My address is: Jim candela 3305 Kissman Dr. Austin, Texas 78728 I got my Gonset G50 cleaned up and transmitting last week. The AM modulation is AWFUL looking on the scope, but that appears to be how those yahoo's designed it. Looks like some simple modifications will make it tolerable. A storm of clip leads, and R-C changes seemed to make it linear at up to +/- 90% modulation at 20 watts carrier output. In stock form it was linear to only +/- 30%, and limited to +50% at the same time as -85%. Pretty crappy. I added plate to grid RC on the 5881's ( 1meg - .033 uf 600v). This cleaned it up a lot, but I needed more peak power. I then lowered the cathode resistor to get more peak modulator power. The lower value cathode resistance only kicks in during transmit ( 350 ohm rcv, 190 ohm xmit). The modulator's tubes in parallel, class A Heising modulation seem to modulate up to +120% now at 22 watts RF output (100% at 25 watts), and I am limited to -85% due the Heising circuit limitations. Today I found a way to cool the modulators a little, and maintain nearly the same peak power. I put a 7K 5 watt WW resistor in series with the modulator screens. The screens are not bypassed, so this drops the screen voltage some, and is another source of negative feedback. Still plenty of gain from my D-104. The scope pattern looks real nice now, and shows perfect symmetry up to 80% modulation. The receiver is another story. It works, but has audio motor boating (when tuning in the 50.4 MHz spot (signal), and tunes like there is regeneration somewhere. I replaced all the P/S electrolytics earlier this week. The receiver might want to kick my butt for a while. I have a real nice FET preamp for 6 meters. I may hook that up someday once I know if this receiver is OK or not. I hooked the G50 to my 80 meter inverted V, and I can copy all kinds of stuff (some cordless phones
RE: [AMRadio] Schematic Needed
...I would rather be clean linear right up to the overload point. I usually use some form of negative cycle attenuation (not loading) to keep the carrier power above zero though. Ultra Modulation is nothing more than a form of controlled carrier with some even-harmonic distortion thrown in. The increase in carrier level is accomplished by increasing the average DC plate voltage to the final. Where does this increased voltage come from? From rectifying some of the audio output from the modulator. The ultramodulation process attenuates the negative half of the audio cycle using a voltage divider. This modification of the sine waveform results in substantial even harmonic distortion. The plate current meter will show an increase under modulation, and if you put a DC voltmeter on the B+ line to the final, you would see that the DC plate voltage increases, too. When I tried ultramodualtion, making an A-B comparison with conventional audio, the reports I got were that ultramodualtion made the audio sound a little raspy, but was not really any louder. I suspect the distortion leaves the false impression that the audio has more punch... the audiophools love it. Using the same modulator minus the ultramodulation circuitry, one can achieve the same positive peak percentage of modulation by taking advantage of the natural asymmetry of the human voice. Just make sure the polarity of the audio feed is correct, and that every stage of the audio chain is capable of handling the audio peaks generated by your voice. Of course, as with ultramodualtion, the modulator must be capable of the peak audio output power capability necessary to modulate in excess of 100% in the positive direction. Otherwise, you just get flat-topping on the positive peaks resulting in splatter and distortion. Don K4KYV _ Protect your PC - get McAfee.com VirusScan Online http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963
[AMRadio] Schematic Needed
Hi Fellow AM'ers; I am restoring / modifying a Gonset G50 six meter transceiver. I have the schematic, and documentation from the Bama ftp sight. The schematic there is of poor quality, and reading component values is next to impossible. Does anyone have a quality print of this schematic? A good print scanned would do as would a 11 X 17 paper copy. I got the transmitter going pretty decent. The stock modulation really stinks, so instead of fixing it Gonset made it a selling feature. With only minor changes it is now approaching decent. I am having problems with the receiver, and the squelch circuit. This is where I really need a readable schematic. Anybody out there with G50 on the air experience? Regards, Jim candela WD5JKO ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Schematic Needed
Hello Jim: I cant scan a schematic for you but can copy mine and send it via post. Let me know if you have not received one yet. My modulation on the G-50 has been described as excellent using a D-104 microphone. The ones I have heard sound good too, but not many lows. The receiver sensitivity in mine is worse than I think it should be, even for its time. I think it was around 6 uV for only 6 dB S+N/N ratio. Have not worked on it lately. My dial drive slips also but hate to tear out the reduction drive (lazy). Good Luck es 73 DE Charlie, K0NG. Quoting Jim candela [EMAIL PROTECTED]: Hi Fellow AM'ers; I am restoring / modifying a Gonset G50 six meter transceiver. I have the schematic, and documentation from the Bama ftp sight. The schematic there is of poor quality, and reading component values is next to impossible. Does anyone have a quality print of this schematic? A good print scanned would do as would a 11 X 17 paper copy. I got the transmitter going pretty decent. The stock modulation really stinks, so instead of fixing it Gonset made it a selling feature. With only minor changes it is now approaching decent. I am having problems with the receiver, and the squelch circuit. This is where I really need a readable schematic. Anybody out there with G50 on the air experience? Regards, Jim candela WD5JKO ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
