[AMRadio] Wilkinson tx
I maintained a Wilkinson AM1000 at WKEX in Blacksburg, VA, about 30 years ago. It stuggled to make 1 kW, and we ran it with a window fan blowing into the open back door, to prevent it from burning out the screen voltage rheostat (power control knob). Eventually I added some fixed R and the part lasted longer. It was pretty much a gutless wonder, similar to the McMartian except it used tetrodes not pentodes. They were made up near Denver. After Guffy Wilkinson passed on, they got bought out by Larcan I believe. John K5PRO
Re: [AMRadio] FS: URM-25D with accessories
Hi Craig, I have been meaning to send you an email for a while. Hope all is better there. How are the SP-600's going? I now have that RCA 77D Mike complete and back from Clarance Kane who has rebuilt and tested it. Are you still looking for one? Hope to see you at Howard's again soon. Best 73's Peter Craig Roberts wrote: For sale: a nice URM-25D signal generator with lid and ALL accessories. It operates to specs and is cosmetically in very good. $100.00 includes shipping in U.S. if paid by Pay Pal at [EMAIL PROTECTED] Many thanks and 73, Craig W3CRR __ 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
Re: [AMRadio] FS: URM-25D with accessories
Hello Peter!! Well, the SP-600s are nearing completion. The original family crisis is over with a good resolution, but my wife's 87 year old mother broke her leg a few weeks ago, and we've been attending to her 24-hour a day needs. She's recovering nicely, if very slowly, however. I hope to get over to Howard's within the next three or four weeks with the receivers -- sooner, if possible. I'm afraid finances won't allow the purchase of the mike before mid-summer, Peter. I'm sorry. See you soon, my friend. Thanks for getting in touch. I look forward to seeing you again. maybe we can all go get lunch this time. VY 73, Craig
[AMRadio] Ooops!
Obviously, my last message was directed toward Peter privately -- but hey!, we're one big happy family here! 73, Craig W3CRR
Re: [AMRadio] Ooops!
I'm glad you Peter shared, Craig. It gave me the opportunity again to drool over the thought of a '77D mic, which is all I'll be able to afford to do for a while yet. ~ Todd KA1KAQ On 5/23/06, Craig Roberts [EMAIL PROTECTED] wrote: Obviously, my last message was directed toward Peter privately -- but hey!, we're one big happy family here! 73, Craig W3CRR __ 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
RE: [AMRadio] Amplifier with input drive to screen grid
Strange indeed Bill! I don't mean to be descending but have you checked to see if you wearing your wife's glasses instead of yours. HIHI It is possible to drive the screens instead of the control grids as a class B zeros bias circuit however it would require neutralizing to work properly. Most folks would opt for the grounded grid configuration where neutralizing is generally not required. I can't see where the meter in the grid circuit would ever show much current unless the rig was once a grounded grid and then was converted to screen driven and they just didn't change the grid meter. Even so 10K in series with the grid meter and no by pass - it just don't make sense to me. John, WA5BXO -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bill Fondren Sent: Tuesday, May 23, 2006 7:44 AM To: AMRadio@mailman.qth.net Subject: [AMRadio] Amplifier with input drive to screen grid I recently traded for a linear that has a strange input circuit, at least to me. The amp is built in a 18 Bud rack mount cabinet weighting about 150 lbs. To heavy for 1 person to handle so I deceided to split the RF deck from the power supply and put it in a taller cabinet along with the exciter. No info was with the unit. I have used it a couple of times and it works fine . It uses a pair of 813's in parallel. I started to draw out the circuit finding that the drive goes to a tuned circuit and then to the sceen grids of the 813's. The control grids are connected together and go to a 10K resistor, the grid current meter and then to grd. No connection to the drive circuit at all other than the interelectrode cap. I guess. The plate circuit seems to be normal. Just wondering if any one has seen something like this before. Bill K5PML __ 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
Re: [AMRadio] Dayton Stuff
Polycomm 62 sold; stil have an Eldico AT-1, Antennascope. Pete On Tue, 16 May 2006 18:27:12 -0500 [EMAIL PROTECTED] writes: Hello Pete: Wish I could go (sob). If you dont sell the Polycom, lets talk. What did you have in Eldico ?? 73 DE Charlie, K0NG ..
Re: [AMRadio] Dayton Stuff
On 5/23/06, Peter Markavage [EMAIL PROTECTED] wrote: Polycomm 62 sold; stil have an Eldico AT-1, Antennascope. I have one of those Pete, minus the top decal. Interesting conversation piece. Also have a set of the last Eldico 'clones' labeled as RELiant instead of Eldico. From all I've seen, the earlier 50s gear was better made than the last of the line. FB on the Polycomm, nice rigs indeed. But I'm waiting patiently for you to get sick of your Lulus. As time permits this spring, the 6m antenna will get put back up, so maybe we can work one of these days when the band opens. Glad you had nice wx for the big convention. 73, Todd KA1KAQ
[AMRadio] Re: Amplifier with input drive to screen grid
It sounds like they were connecting the 813s as zero-bias triodes, more often done in modulator service. Don't know why they'd do this instead of run them GG in this application, though, unless there was an appreciable difference in gain. Maybe the guy just wanted to experiment with something different. I don't see how the grid current meter connected as you described would register any grid current at all, 'cuz I can't see that the control grid would go positive wrt the cathode in that configuration. Does it move off the peg at all?? 73, -Larry/NE1S Bill Fondren writes: I recently traded for a linear that has a strange input circuit, at least to me. The amp is built in a 18 Bud rack mount cabinet weighting about 150 lbs. To heavy for 1 person to handle so I deceided to split the RF deck from the power supply and put it in a taller cabinet along with the exciter. No info was with the unit. I have used it a couple of times and it works fine . It uses a pair of 813's in parallel. I started to draw out the circuit finding that the drive goes to a tuned circuit and then to the sceen grids of the 813's. The control grids are connected together and go to a 10K resistor, the grid current meter and then to grd. No connection to the drive circuit at all other than the interelectrode cap. I guess. The plate circuit seems to be normal. Just wondering if any one has seen something like this before. Bill K5PML
[AMRadio] 20M AM Activity
I'd like to stir up some activity on 14.286 AM. There used to be quite an active group up there with W6HQI(SK), W8VYZ, WA4KCY, W6HDU, and others. I'd join them from time-to-time back in the latter 80's and early 90's. I talked to W8VYZ last weekend on 40M, and he said he still gets up there, but I've not heard him when I've looked in recent weeks. I called a CQ w(ith one of my Viking Is) on the above-mentioned frequency last Wed. nite, and a pleasent QSO ensued with a ham that I had never before met, although he lives all of 15 miles from me! Then last nite I called CQ (using the 30s homebrew rig - PP 812As modulated by 805s - 1st time this rig has been on 20M!) and this resulted in 3 consecutive solid QSOs - N4VIC/mobile in GA, N4OYT (also in GA, but not moile), and KJ0L (IA). None of these guys, including last week's qso, were regular AM ops, but they put their rigs on AM for the occaision. So, I guess all of this is just meant to encourage folks to check out 14.286 and call an AM CQ now and then - you get to meet new folks other than the (usually local) group of regulars that are on the lower bands. I'll be spending more time up there, I know. Look for me between 8-10PM, especially Monday evenings. 73, -Larry/NE1S
[AMRadio] URM-25D sold
The signal generator has been sold. Many thanks to all who replied. 73, Craig W2CRR
[AMRadio] BTA-1R2
To all owners or those familiar with the BTA-1R series of transmitters: The Power Raise/Lower variable resistor (1R405) is connected to the motor unit which turns it when switch #1S202 is operated. The connection between the motor and the rheostat on mine is gone and I can't seem to find a legible picture showing exactly how the two circular pieces (the one the motor and the one on the resistor) connect together. Mine had a make shift piece of felt held securely by a radiator hose clamp at one time, but this too was broken. Can someone take a look at their 1R and let me know how they are really supposed to be connected. It appears that this may have had some kind of slip type clutch arrangement originally, but I could be way off base on that. Any help and advice will be greatly appreciated. 73, Rick/K5IZ
RE: [AMRadio] BTA-1R2
Check with davidsarnoff.com they have all the docs for that unit Brad KB7FQR -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Rick Brashear Sent: Tuesday, May 23, 2006 11:30 AM To: AMRadio@mailman.qth.net Subject: [AMRadio] BTA-1R2 To all owners or those familiar with the BTA-1R series of transmitters: The Power Raise/Lower variable resistor (1R405) is connected to the motor unit which turns it when switch #1S202 is operated. The connection between the motor and the rheostat on mine is gone and I can't seem to find a legible picture showing exactly how the two circular pieces (the one the motor and the one on the resistor) connect together. Mine had a make shift piece of felt held securely by a radiator hose clamp at one time, but this too was broken. Can someone take a look at their 1R and let me know how they are really supposed to be connected. It appears that this may have had some kind of slip type clutch arrangement originally, but I could be way off base on that. Any help and advice will be greatly appreciated. 73, Rick/K5IZ __ 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: 7.1.394 / Virus Database: 268.7.0/345 - Release Date: 5/22/2006
Re: [AMRadio] BTA-1R2
Thanks Brad, I have an email into them to see if they have the manual. 73, Rick/K5IZ uvcm inc. wrote: Check with davidsarnoff.com they have all the docs for that unit Brad KB7FQR
Re: [AMRadio] 20M AM Activity
I talked to Bill, W8VYZ on 7290 kHz for over an hour while I was mobiling out to Dayton. He is getting on 20M regularly, but most recently he has been signing on at about 2230 EDT. Apparently the band has been very good lately and an AM station from New Zealand running 200 watts has been a regular on frequency and near that time.. Nice to hear about your activity. I'll try to fire up on 20M more frequently. Dale KW1I
Re: [AMRadio] BTA-1R2
Rick, Its a typical WELL INSULATED flex shaft coupling with the required size holes. The full 3.1 kv B+ is on the rheostat. Larry W3LW At 02:29 PM 5/23/2006, you wrote: To all owners or those familiar with the BTA-1R series of transmitters: The Power Raise/Lower variable resistor (1R405) is connected to the motor unit which turns it when switch #1S202 is operated. The connection between the motor and the rheostat on mine is gone and I can't seem to find a legible picture showing exactly how the two circular pieces (the one the motor and the one on the resistor) connect together. Mine had a make shift piece of felt held securely by a radiator hose clamp at one time, but this too was broken. Can someone take a look at their 1R and let me know how they are really supposed to be connected. It appears that this may have had some kind of slip type clutch arrangement originally, but I could be way off base on that. Any help and advice will be greatly appreciated. 73, Rick/K5IZ __ 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
Re: [AMRadio] BTA-1R2
If you want I can take a close up photo of mine and Email it to you. --- Rick Brashear [EMAIL PROTECTED] wrote: To all owners or those familiar with the BTA-1R series of transmitters: The Power Raise/Lower variable resistor (1R405) is connected to the motor unit which turns it when switch #1S202 is operated. The connection between the motor and the rheostat on mine is gone and I can't seem to find a legible picture showing exactly how the two circular pieces (the one the motor and the one on the resistor) connect together. Mine had a make shift piece of felt held securely by a radiator hose clamp at one time, but this too was broken. Can someone take a look at their 1R and let me know how they are really supposed to be connected. It appears that this may have had some kind of slip type clutch arrangement originally, but I could be way off base on that. Any help and advice will be greatly appreciated. 73, Rick/K5IZ __ 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 __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
Re: [AMRadio] BTA-1R2
Thanks. Mine has a porcelain coupling isolating the rheostat from the motor drive shaft, but what concerns me is without some kind of slip apparatus on the two 1 3/8 hubs that connect the rheostat shaft coupling to the motor drive shaft coupling it would be possible to do damage to either the motor or resistor if either limit were reached and the power still applied to the motor and gearbox. It appears this is the factory installation, but maybe it's been modified? Rick/K5IZ Larry Will wrote: Rick, Its a typical WELL INSULATED flex shaft coupling with the required size holes. The full 3.1 kv B+ is on the rheostat. Larry W3LW
Re: [AMRadio] BTA-1R2
If you don't mind John I would really appreciate it. I'd hate to mess this part up as I doubt it would be easy to replace. Thanks, Rick/K5IZ John Wright wrote: If you want I can take a close up photo of mine and Email it to you. --- Rick Brashear [EMAIL PROTECTED] wrote:
[AMRadio] Re - response to input to screen grid amplifier
Thanks for the quick response to my questions concerning this amp. John, I was ready for some salty remarks (hihi) and I did clean my glasses and take a second or third look at the thing. I thought I had missed something since going to USAF Radio School in the early 50's. Guess that tells u why I mess with vacumn tube rigs. Anyway thought I better get some expert opinions before starting to cut and chop to get it to a more conventional type. The construction of the amp is above average for a homebrew rig. A couple of other things There is a RFC choke coming off the G1 connections going to the 10K resistor then to the grid meter (0-30ma shunted with a 50 ohm 10 watt resistor) It does read about half scale peaking normal as u tune the grid circuit. Also a .01 bypass cap at the meter. The input coil is grounded in the middle through a RFC choke making a double coil, tuned by a split stator cap. One of the tuned circuits goes directly to the screen grids and the other feeds the neutralizing voltage back to the input from the plate. No bias circuits of any kind. The few times I used it I got good reports using a Elmac AF-67 exciter. Will probably change it to a more conventional type. Thanks again Bill K5PML
RE: [AMRadio] BTA-1R2
Rick I thought you had a BTA1R1... With it just run out to Masons and take all the pixs you want of the conversion...Very well done by Mason and John King K5CDV... As you know John is the CE of WRR.. He has done lots of These conversions... Bob W1PE -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Rick Brashear Sent: Tuesday, May 23, 2006 1:57 PM To: Discussion of AM Radio Subject: Re: [AMRadio] BTA-1R2 Thanks Brad, I have an email into them to see if they have the manual. 73, Rick/K5IZ uvcm inc. wrote: Check with davidsarnoff.com they have all the docs for that unit Brad KB7FQR __ 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] Dallas Hamcom
Hi All... There will be an AM Forum at 3PM Friday the 9th of June at 1500 At this years HAMCOM. HAMCOM is the 9th and 10th in Plano, TX. Check out the website at www.hamcom.org for all the info. Planed right now is an AM BBQ at Jims W5WN at 18:30 sponsored by the NOSAM Group. The New Old Stock AM group has been around a number of years as a social AM group. Let us know in advance if you want to come. Best 73's Bob W1PE
Re: [AMRadio] Re - response to input to screen grid amplifier
If it ain't broke, don't fix it. 73, Ed Richards K6UUZ Simi Valley, Ca 93065 Home of the Air Force 1 pavilion On Tue, 23 May 2006 14:04:19 -0700 (PDT) Bill Fondren [EMAIL PROTECTED] writes: Thanks for the quick response to my questions concerning this amp. John, I was ready for some salty remarks (hihi) and I did clean my glasses and take a second or third look at the thing. I thought I had missed something since going to USAF Radio School in the early 50's. Guess that tells u why I mess with vacumn tube rigs. Anyway thought I better get some expert opinions before starting to cut and chop to get it to a more conventional type. The construction of the amp is above average for a homebrew rig. A couple of other things There is a RFC choke coming off the G1 connections going to the 10K resistor then to the grid meter (0-30ma shunted with a 50 ohm 10 watt resistor) It does read about half scale peaking normal as u tune the grid circuit. Also a .01 bypass cap at the meter. The input coil is grounded in the middle through a RFC choke making a double coil, tuned by a split stator cap. One of the tuned circuits goes directly to the screen grids and the other feeds the neutralizing voltage back to the input from the plate. No bias circuits of any kind. The few times I used it I got good reports using a Elmac AF-67 exciter. Will probably change it to a more conventional type. Thanks again Bill K5PML __ 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
Re: [AMRadio] Dayton Stuff
Thanks for the reply Peter. Always wanted to try a PolyCom. Maybe some day ? Already have antenna scope, sorry. Thanks again 73 DE Charlie K0NG ..
Re: [AMRadio] Ooops!
Enjoyed the news here Craig !! (HI) 73 DE K0NG ..
RE: [AMRadio] Re - response to input to screen grid amplifier
Bill does the screen have a DC path to ground through the tuning coil? I see no way that you can have grid current with no RF on the Grid. Perhaps there is a hidden wire connecting the grid and the screen together. I am sending you a PDF on the 813 just to make sure that you have a correct one. John, WA5BXO
Re: [AMRadio] BTA-1R2
Rick, I will be on the Gray Hair Net on 1945 at 20:30 local time tonite so I'll go look at mine before that and send you a note. As I remember they just relied on a stall, no slip. Larry At 04:47 PM 5/23/2006, you wrote: Thanks. Mine has a porcelain coupling isolating the rheostat from the motor drive shaft, but what concerns me is without some kind of slip apparatus on the two 1 3/8 hubs that connect the rheostat shaft coupling to the motor drive shaft coupling it would be possible to do damage to either the motor or resistor if either limit were reached and the power still applied to the motor and gearbox. It appears this is the factory installation, but maybe it's been modified? Rick/K5IZ Larry Will wrote: Rick, Its a typical WELL INSULATED flex shaft coupling with the required size holes. The full 3.1 kv B+ is on the rheostat. Larry W3LW __ 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
Re: [AMRadio] 20M AM Activity
Dale, I too was on 20 am about 1 month ago, and I talked to Mr. Bill, VYZ. He was sipping from his W8VYZ coffee cup from Cafe Express. No royalties go to him, but he said he doesn't care. I think he is flattered at the interest in his OB comments. I was using my QRO 20a and driving that Gonset GSB-201 I bought from you several years ago. It's still chugging along fine. tnx. Jim JKO --- Radio Station KW1I [EMAIL PROTECTED] wrote: I talked to Bill, W8VYZ on 7290 kHz for over an hour while I was mobiling out to Dayton. He is getting on 20M regularly, but most recently he has been signing on at about 2230 EDT. Apparently the band has been very good lately and an AM station from New Zealand running 200 watts has been a regular on frequency and near that time.. Nice to hear about your activity. I'll try to fire up on 20M more frequently. Dale KW1I __ 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
RE: [AMRadio] Re - response to input to screen grid amplifier
This sounds like a class C linear screen driven amp. I couldn't find the article on it but W9VMQ built such an amp using 6DQ5's in the early 60's. I think he also did some experimenting with the 813 also. I think the article was in Ham Radio magazine. Maybe someone can do a search for it. Probably around 1963 to 1965? 73 Gary K4FMX -Original Message- From: [EMAIL PROTECTED] [mailto:amradio- [EMAIL PROTECTED] On Behalf Of John E. Coleman (ARS WA5BXO) Sent: Tuesday, May 23, 2006 7:34 PM To: 'Discussion of AM Radio' Subject: RE: [AMRadio] Re - response to input to screen grid amplifier Bill does the screen have a DC path to ground through the tuning coil? I see no way that you can have grid current with no RF on the Grid. Perhaps there is a hidden wire connecting the grid and the screen together. I am sending you a PDF on the 813 just to make sure that you have a correct one. John, WA5BXO __ 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] 10 Meters Open
It's open from Mississippi to w9 and w0 land. I'll monitor 29.0 for the next little while in case someone wants to try an AM qso there. Mike Duke, K5XU American Council of Blind Radio Amateurs
Re: [AMRadio] 10 Meters Open
There were 8 beacons heard here (Central NY), along with several cw contacts...no takers on 29.0 klc - Original Message - From: Mike Duke, K5XU [EMAIL PROTECTED] Date: Tuesday, May 23, 2006 8:27 pm Subject: [AMRadio] 10 Meters Open To: Discussion of AM Radio amradio@mailman.qth.net It's open from Mississippi to w9 and w0 land. I'll monitor 29.0 for the next little while in case someone wants to try an AM qso there. Mike Duke, K5XU American Council of Blind Radio Amateurs __ 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
Re: [AMRadio] 10 Meters Open
I used to work WA5TLP in Williston, N.D. on 29.050. Seems like he was using a ricebox rig of some kind. Joe W4AAB - Original Message - From: Mike Duke, K5XU [EMAIL PROTECTED] To: Discussion of AM Radio amradio@mailman.qth.net Sent: Tuesday, May 23, 2006 7:27 PM Subject: [AMRadio] 10 Meters Open It's open from Mississippi to w9 and w0 land. I'll monitor 29.0 for the next little while in case someone wants to try an AM qso there. Mike Duke, K5XU American Council of Blind Radio Amateurs __ 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
