RE: [AMRadio] Gonset G-76
I did some work on it today. First off, I replaced the tube I was using for the audio driver, I had a 6c4 (triode) in there, some past attempt to clean things up, and strangely enough, only one pin needed to be moved. That gave me a little more audio drive. I also increased the RF grid drive by bypassing a 4700 ohm resistor in the B+ line to the rf driver tube. I found my G76 does an odd thing, if you go to the tune position and peak the grid drive, when you go to the high power mode, the peak shifts. What I did was go to drive level 2 and then tune the grid drive to get minimum plate current on the output tube, measuring the grid voltage had that position the highest, then go back to the maximum grid drive position on the drive level switch. I don't know if its something with my G76 but if the grid drive is low at all, the positive modulation falls off badly. Next was to add some neg feedback from the modulated B+ to the driver tube grid, bypassing it for highs to prevent phase shift positive feedback (supersonic). I tried different amounts and parts values and got the rig sounding not bad, before the feedback, the highs were extreme, with very little lows at all. The amount of feedback acts like a tone control, little is very bright, more feedback rolls that off and makes things sound good for a D104. The end result was about 50 to 60 watts output, positive modulation is up about 80% at 100% neg, if I exceed 100% neg modulation, the positive will go up to 110%. I checked out the receive section, I had removed the resistors across the IF cans (narrows the IF bandwidth) and the 5pf caps bridging from primary to secondary (also narrows the bandwidth). besides the noisy audio IC chip, the receiver works well. I need to go back and change the B+ source to the audio stages, and take if off the relay so the tubes are not on all the time, with a stock rig they do the receive audio, but they don't on mine, no reason to leave them on I also went through my 6DQ5 and 6DQ6 tube collection, testing them out, some were bad, some were good... I did not get a chance to get it on 40 today, I had to go out, but maybe tomorrow I can work someone with it. I got on 80 meters tonight, a very rare thing for me, and the 80 meter antenna (if you can call it that) was acting crazy from the snow. I got to get rid of that thing and put up something that works. Back to the loading coil setup I guess, but in a different spot not directly over the house... Fun with radio... Brett N2DTS > Brett, > > >You are correct about the rolled off low frequency > response on a G-76. > That said, these rigs "stock" seem to have more lows than say a Heath > Apache. One caution however is that the stock iron cannot > take a lot off > bass, so any bass to midrange boosting attempt needs to take that into > consideration. Since a "flat" transmitter response of say 80 > hz to 4000 hz > will sound bassy and muffled in the average receiver with a 5-6 Kc IF > bandwidth (@ - 6db), you might add consider adding > additional low end to > that G-76, but do so at somewhere between 3-10 db down from > the 1 Khz level. > At 6 db down, the iron only has to handle 1/4th the power, so > low frequency > core saturation is likely eliminated, and you can still > broadcast down to 80 > hz. Maybe bridge that 470 pf with a series R-C instead of > just making a > bigger C, and you could manipulate the hi-freq roll off with > some R & C > additions instead of just that .001 to ground. > > It would be interesting to take that G-76, and add a > voltage divider to > the modulated B+ so that you can put the scope in X:Y mode to > look at the > Trapezoid pattern. I use this mode all the time with my 20a + linear > combination, and the Trapezoid is VERY useful towards setting > up the linear > for a minimum of distortion. With plate modulation, the > Trapezoid is less > necessary, but still useful when setting up, or evaluating a > transmitter. A > plate modulated class C amplifier usually modulates upward better with > increasing driveto a point. > > Jim > > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Brett gazdzinski > Sent: Thursday, February 09, 2006 9:22 PM > To: 'Discussion of AM Radio' > Subject: RE: [AMRadio] FS: restored Gonset G-76 > > > I guess I have different expectations then most here. > I would say its not possible to have the G76 sound good > on receive or transmit, what with the design and parts > they used. > You have a 470pf (yes, that pico)coupling cap between the 1st and > second stage microphone amplifier, and they inject the > receive audio in there also, and that uses another 470pf (yes pico) > coupling cap, with a .001 to ground. > > How can anyone get nice lows with a 470pf coupling cap, or highs > with a .001 to ground. I would think a good telephone would have > a better frequency response. > > We wont even get into the modulator grid drive
[AMRadio] FS - HQ170C
Have an HQ-170C for sale. Works OK but probably could use tube check and alignment. Haven't had time to work with it . No dents, rust,etc but a couple of spots w/ paint rub off. Front panel gud. Gud shape otherwise. It has an original manual. Picture at http://www.qsl.net/wa0ahq/hq170.jpg Asking $225+shipping.
RE: [AMRadio] REPLY TO addresses - WAS: restored Gonset G-76
Hey Dan - The people that make the free FireFox browser (now > 15% of the market and climbing!) also have an email client, a calender/scheduler, and an HTML editor as separate programs. They are all very high quality and 100%. 73, Mark W1EOF > -Original Message- > From: Dan wright [mailto:[EMAIL PROTECTED] > Sent: Saturday, February 11, 2006 4:11 PM > To: [EMAIL PROTECTED]; Discussion of AM Radio > Subject: Re: [AMRadio] REPLY TO addresses - WAS: restored Gonset G-76 > > > > > > >Dan if you got a better e-mail program like PEGASUS (it's free!) > >you could SELECT the reply to go to whomever you wanted. > > Hey Bry!! > > Thanks for the nice note(8-> > > I use Eudora.used it for years and yearsand if I take the > time to LOOK > at what I'm doin' , I can also select who the recipient is. ALTHOUGH > I need to check out PEGASUS > > Right now I am struggling with dialup and the phone lines > are having problems and are getting slower and slower. > > In a week or so I have an appointment to get RoadRunner > installed and after that, I'll be downloading stuff!!! > > thanks again!! > > 73 de Dan -- WAØJRD .. > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > AMfone Website: http://www.amfone.net > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.375 / Virus Database: 267.15.6/257 - Release Date: 2/10/06 > -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.375 / Virus Database: 267.15.6/257 - Release Date: 2/10/06
RE: [AMRadio] REPLY TO addresses
Brian - Outlook doesn't control who you reply to. There is a button for "Reply" and a button for "Reply All" just like all the other popular email programs. The problem is in the default setting for a particular email list. Usually you have a choice which way a "reply" goes. The problem is that no matter which way it's setup it is wrong for some percentage of the list members. Some people compensate by always clicking "ReplyAll" which hits both the individual and the list. This is handy for when you intentionally desire to reply immediately and separately to the individual AND want to share the response with the other list members (like this email). That's the only case one should use "ReplyAll". It's just something that you need to get used to. No software can reolve all the decisions, and as you imply nor should they. 73, Mark W1EOF > -Original Message- > From: Brian Carling [mailto:[EMAIL PROTECTED] > Sent: Saturday, February 11, 2006 3:24 PM > To: Discussion of AM Radio > Subject: [AMRadio] REPLY TO addresses - WAS: restored Gonset G-76 > > > Dan if you got a better e-mail program like PEGASUS (it's free!) > you could SELECT the reply to go to whomever you wanted. > > The sender, the list, the CC: etc. - I would hate to go to Outlook > or something that takes control of who you reply to! > > A lot of these lists force people to reply to the list AND to the > sender so you end up getting 2 or 3 copies of the reply in > some cases. The Glowbugs group is chronic about that! > > http://www.pmail.com/ > > Worth having. I have used it for years. Has some great mail > filtering and folder features that lets you really organize > multiple subscribed lists/groups extremely well. > > YMMV - 73 de AF4K, Bry > > On 8 Feb 2006 at 12:49, Dan wright wrote: > > > > > > > WELL HELL! > > > > It was NOT my intention to send this to the list. > > I apologize both to Craig and to the list. > > > > However I am not pissed or anything about the rig. There are several > > very good reasons it may have worked when he checked it, and now it > > doesn't. > > > > I kinda wish this list had a "reply to" that went > > to the sender and not the list. > > This ain't the first time I have been burned. It's my fault, I > need to check > > the address fields more carefully.so once again I apologize!! > > > > Dan -- WAØJRD .. > > > > __ > > AMRadio mailing list > > Home: http://mailman.qth.net/mailman/listinfo/amradio > > Help: http://mailman.qth.net/mmfaq.html > > Post: mailto:AMRadio@mailman.qth.net > > AMfone Website: http://www.amfone.net > > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb > > > > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > AMfone Website: http://www.amfone.net > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.375 / Virus Database: 267.15.6/257 - Release Date: 2/10/06 > -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.375 / Virus Database: 267.15.6/257 - Release Date: 2/10/06
Re: [AMRadio] REPLY TO addresses - WAS: restored Gonset G-76
Dan if you got a better e-mail program like PEGASUS (it's free!) you could SELECT the reply to go to whomever you wanted. Hey Bry!! Thanks for the nice note(8-> I use Eudora.used it for years and yearsand if I take the time to LOOK at what I'm doin' , I can also select who the recipient is. ALTHOUGH I need to check out PEGASUS Right now I am struggling with dialup and the phone lines are having problems and are getting slower and slower. In a week or so I have an appointment to get RoadRunner installed and after that, I'll be downloading stuff!!! thanks again!! 73 de Dan -- WAØJRD ..
[AMRadio] REPLY TO addresses - WAS: restored Gonset G-76
Dan if you got a better e-mail program like PEGASUS (it's free!) you could SELECT the reply to go to whomever you wanted. The sender, the list, the CC: etc. - I would hate to go to Outlook or something that takes control of who you reply to! A lot of these lists force people to reply to the list AND to the sender so you end up getting 2 or 3 copies of the reply in some cases. The Glowbugs group is chronic about that! http://www.pmail.com/ Worth having. I have used it for years. Has some great mail filtering and folder features that lets you really organize multiple subscribed lists/groups extremely well. YMMV - 73 de AF4K, Bry On 8 Feb 2006 at 12:49, Dan wright wrote: > > > WELL HELL! > > It was NOT my intention to send this to the list. > I apologize both to Craig and to the list. > > However I am not pissed or anything about the rig. There are several > very good reasons it may have worked when he checked it, and now it > doesn't. > > I kinda wish this list had a "reply to" that went > to the sender and not the list. > This ain't the first time I have been burned. It's my fault, I need to check > the address fields more carefully.so once again I apologize!! > > Dan -- WAØJRD .. > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > AMfone Website: http://www.amfone.net > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb >
[AMRadio] New Additions to the CRA website
Go to the CRA website and click on the "Album" section to see two new articles with pictures on the 516F-2 power supply conversions and the replacement capacitor C106 for the KWM-2. These excellent articles were prepared by Stu, K2QDE, a frequent contributor to the Collins Journal publication. For the very best Collins website, that is always updated on a regular basis, rely on the CRA. Help support the CRA - join today. Dave, W3ST Publisher of the Collins Journal Secretary to the Collins Radio Association www.collinsra.com - the CRA Website Now with PayPal CRA Nets: 3805 Khz every Monday at 8 PM EST and 14255 every Saturday at 12 Noon EST
RE: [AMRadio] FS: restored Gonset G-76
Brett, You are correct about the rolled off low frequency response on a G-76. That said, these rigs "stock" seem to have more lows than say a Heath Apache. One caution however is that the stock iron cannot take a lot off bass, so any bass to midrange boosting attempt needs to take that into consideration. Since a "flat" transmitter response of say 80 hz to 4000 hz will sound bassy and muffled in the average receiver with a 5-6 Kc IF bandwidth (@ - 6db), you might add consider adding additional low end to that G-76, but do so at somewhere between 3-10 db down from the 1 Khz level. At 6 db down, the iron only has to handle 1/4th the power, so low frequency core saturation is likely eliminated, and you can still broadcast down to 80 hz. Maybe bridge that 470 pf with a series R-C instead of just making a bigger C, and you could manipulate the hi-freq roll off with some R & C additions instead of just that .001 to ground. It would be interesting to take that G-76, and add a voltage divider to the modulated B+ so that you can put the scope in X:Y mode to look at the Trapezoid pattern. I use this mode all the time with my 20a + linear combination, and the Trapezoid is VERY useful towards setting up the linear for a minimum of distortion. With plate modulation, the Trapezoid is less necessary, but still useful when setting up, or evaluating a transmitter. A plate modulated class C amplifier usually modulates upward better with increasing driveto a point. Jim -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Brett gazdzinski Sent: Thursday, February 09, 2006 9:22 PM To: 'Discussion of AM Radio' Subject: RE: [AMRadio] FS: restored Gonset G-76 I guess I have different expectations then most here. I would say its not possible to have the G76 sound good on receive or transmit, what with the design and parts they used. You have a 470pf (yes, that pico)coupling cap between the 1st and second stage microphone amplifier, and they inject the receive audio in there also, and that uses another 470pf (yes pico) coupling cap, with a .001 to ground. How can anyone get nice lows with a 470pf coupling cap, or highs with a .001 to ground. I would think a good telephone would have a better frequency response. We wont even get into the modulator grid driver/audio output transformer, which makes the dx100 driver transformer look massive. As an audio output transformer, it looks like it would be good for about 1/4 watt output. The mike input amp has a 470K resistor to ground, no way you are getting any lows at all thereneeds to be like 5 meg for lows with a D104. I did some playing around with it tonight, and found two problems, a bad 12ax7 mike amp, and also found the modulation gets better with much more grid drive. I have some changes to do in the mike amp stage, but it sounds back to its old self as long as the output power is below 60 watts. The audio waveform looks ok up to 100% mod at 60 watts, any more and it starts looking funky, I did not look into the driver tube and its circuit yet, or the clamp tube screen circuit in the RF output. Brett N2DTS > > Hi Guys, > > I have been following this thread and I also agree with Charlie. > My G76 gets great audio reports as it is. I am using a D-104 and have > very good audio reports. I am currently listening to a group on the > East Coast using a a 5" Motorola Micor speaker and it sounds great. > Power out is around 70 - 75 watts into a sloper. I use it to > check into > the Midwest Classic Radio net on Saturday morning on 3885, the DX-60 > net on Sunday morning on 3880, on Tuesday the Southeast AM > Radio net on > 3885, and the First Wednesday CCA AM net on 3880. Believe me if it > sounded BAD I would get chastized on the CCA net since I am the > coordinator of the event. (defense if needed) My 32V-3 is under going > major surgery and some day when I am retired it will get finished. We > encourage the use of anything on the CCA net that runs AM and I am > living proof that we abide by that. > > Anyone out there using a G-76 mobile? I have the mobile supply and > would like to give it a try. > > 73 Larry WA9VRH > > > > On Thursday, February 9, 2006, at 06:44 PM, [EMAIL PROTECTED] wrote: > > > > > Jim: I agree with all of your comments as my G76 works well as is. > > Not that anything cant be improved butif it aint broke .. > > Maybe in this case, there is a problem ?? > > > > Regards to all, Charlie, K0NG . > > > > > > __ > > AMRadio mailing list > > Home: http://mailman.qth.net/mailman/listinfo/amradio > > Help: http://mailman.qth.net/mmfaq.html > > Post: mailto:AMRadio@mailman.qth.net > > AMfone Website: http://www.amfone.net > > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb > > > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio >
