Re: [AMRadio] Suggestions Please
From: Jeff Edmonson [EMAIL PROTECTED] ...but, running a rig, with an audio response of 50hZ to 5kHz? Where does the excessive line stop? When band conditions (congestion) don't permit it. When the band is crowded, I find receiving bandwidth greater than 6 kc/s unuseable. Under congested condx, audio beyond 3.5 kc/s will probably not be heard anyway, so argument can be made that it should not be transmitted, since it only wastes spectrum space. But under less crowded condx, if you can reasonably expect to be able to open your rx bandwidth to 8-10 kc/s, the extra audio can make a difference, and there is prenty of room in the band for other stations to operate besides 2-3 kc/s away from at AM carrier. That's why I have the choice of two low-pass audio filters in my rig. On 10m. I often run with no filter. On the low end, the human voice goes down to about 100 cps or below. The voice sounds more natural when these frequencies are present, but it can be counterproductive to boost them to generate jukebox sound. Just keep the transmitter response flat and use a good microphone. If bass frequencies are transmitted, they must be balanced by the highs, or else the signal will sound bassy and will be unintelligible under noisy/QRM condx. I balance my bass by using a pre-emphasis curve beginning at 800 cps and reaching about 10 dB at 2000 cps and above. I then sharply cut off the highs above 3400 cps, or gradually cut them off above 5000 cps, selecting the appropriate passive L-C filter. Don K4KYV _ MSN Photos is the easiest way to share and print your photos: http://photos.msn.com/support/worldwide.aspx
Re: [AMRadio] Suggestions Please
Hi Bill, Thanks for your thoughts. I hadn't considered the possibility of it being a toroid. That would help to explain the size. I'm going to build u pa modulator deck and wee how it works out. Thanks and 73, Ed N3CMI Bill Smith [EMAIL PROTECTED]To: amradio@mailman.qth.net .com cc: Sent by: Subject: Re: [AMRadio] Suggestions Please [EMAIL PROTECTED] man.qth.net 07/24/02 03:17 PM Please respond to amradio They are supposed to work quite well, and are deceptively small. Probably torroidal. Have some also, but no plans at present. 73 de Bill, AB6MT [EMAIL PROTECTED] - Original Message - From: [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Wednesday, July 24, 2002 12:57 PM Subject: Re: [AMRadio] Suggestions Please Hello all, Related to this thread -- I have several ART-13 mod. transformers: P-P 811s to 813 final. They don't look like they have a lot of core cross section. Still, it might be fun to build something up using one. Has anyone had good results with this mod iron? I don't expect a high powered rig; just somehting different from my DX-100 or Viking II. I thought I'd build up the modulator, get that working, then move onto an RF deck. Any thoughts? Thanks and 73, Ed N3CMI ___ 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] Suggestions Please
remember that this xformer is rated at fifty watts, the 12th edition of the RADIO Handbook has a nice 100 watt (max) modulator using pr of 811 Not (A) 1250 volts to do this, also the Z is very high, something like 7500 ohms on the output side. - Original Message - From: [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Wednesday, July 24, 2002 3:57 PM Subject: Re: [AMRadio] Suggestions Please Hello all, Related to this thread -- I have several ART-13 mod. transformers: P-P 811s to 813 final. They don't look like they have a lot of core cross section. Still, it might be fun to build something up using one. Has anyone had good results with this mod iron? I don't expect a high powered rig; just somehting different from my DX-100 or Viking II. I thought I'd build up the modulator, get that working, then move onto an RF deck. Any thoughts? Thanks and 73, Ed N3CMI ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.374 / Virus Database: 209 - Release Date: 07/09/2002
Re: [AMRadio] Suggestions Please
John, You have received several replies referring you to 1960s ARRL Handbooks. If you need one, I have a 1963 issue available. It looks good as new. Maybe I never used it! You can have it for $15, and I will pay postage.Jim - Original Message - From: John Beasley [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Monday, July 22, 2002 11:07 AM Subject: [AMRadio] Suggestions Please Gentlemen: I have decided to try homebrewing an amplifier. I would like to start out modestly. I am looking for any suggestions for a design for single band amplifier using an 813. (I have a lot of these). I would like to avoid band switching to keep things simple. Thank You WAØSTX ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Suggestions Please
Hello all, Related to this thread -- I have several ART-13 mod. transformers: P-P 811s to 813 final. They don't look like they have a lot of core cross section. Still, it might be fun to build something up using one. Has anyone had good results with this mod iron? I don't expect a high powered rig; just somehting different from my DX-100 or Viking II. I thought I'd build up the modulator, get that working, then move onto an RF deck. Any thoughts? Thanks and 73, Ed N3CMI
Re: [AMRadio] Suggestions Please
Hi John, early 60's ARRL handbook has single band 2 X 813 kilowatts, nice compact layout Bill ColemanN2BC http://home.stny.rr.com/n2bc - Original Message - From: John Beasley [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Monday, July 22, 2002 11:07 AM Subject: [AMRadio] Suggestions Please Gentlemen: I have decided to try homebrewing an amplifier. I would like to start out modestly. I am looking for any suggestions for a design for single band amplifier using an 813. (I have a lot of these). I would like to avoid band switching to keep things simple. Thank You WAØSTX ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Suggestions Please
HiThere are MANY examples of single band 813 amps in the old handbooks. I have a 1963 open now, and it gives a very good explanation, pics and componant list. Also shows a power supply and control circuits. Good luck..Al/W8FAX --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html The reason this message is shown is because the post was in HTML or had an attachment. Attachments are not allowed. Please post in Plain-Text only.---
RE: [AMRadio] Suggestions Please
The 1956 handbook has a very nice 500 watt class C all band 813 transmitter on page 198. I had that item in my hands many years ago. It was given to me by the High school I went to. I operated it and enjoyed it very much for a couple years. It also had the 811 modulators and the supplies in a rack. I did not know at that time that it was THE TRANSMITTER documented in the handbook until years later, when I found it in the 1956 handbook at a ham fest. When I opened the book and saw THAT transmitter on page 198, I almost cried! It was like looking at the gost of a long lost friend. I parted it out (kept the parts), and some of it is here and there in my 4-1000 rig, and the mod transformer is now in my DX100 (art-13 type). The final tank circuit is now my antenna tuner. Anyway... check it out. It is a beauty! Sometimes I just look at those pictures and think back when I was 16 yaers old on 11 meters with that thing (really)! My father insisted I get my license, so It was the start of my hamming. Every solder connection was right where I remembered it to be. Memories of the 813. George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Monday, July 22, 2002 3:17 PM To: amradio@mailman.qth.net Subject: Re: [AMRadio] Suggestions Please HiThere are MANY examples of single band 813 amps in the old handbooks. I have a 1963 open now, and it gives a very good explanation, pics and componant list. Also shows a power supply and control circuits. Good luck..Al/W8FAX --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html The reason this message is shown is because the post was in HTML or had an attachment. Attachments are not allowed. Please post in Plain-Text only.--- ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Suggestions Please
Thanks Al, I'll find one of those handbooks and take a look ! 73 - Original Message - From: [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Monday, July 22, 2002 2:17 PM Subject: Re: [AMRadio] Suggestions Please HiThere are MANY examples of single band 813 amps in the old handbooks. I have a 1963 open now, and it gives a very good explanation, pics and componant list. Also shows a power supply and control circuits. Good luck..Al/W8FAX --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html The reason this message is shown is because the post was in HTML or had an attachment. Attachments are not allowed. Please post in Plain-Text only.--- ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Suggestions Please
J- Take a look at the last few issues of Electric Radio (maybe March thru May). The big rig articles are for a rack mounted 813 by 813 am transmitter. I followed these closely and am building my own son of big rig.. (The author is helpful and answers emails.) I am using articles from the late fifties ARRL and Editors and Engineers Radio Handbooks (available on eBay). Great fun!! Also great help from AMers on this site. I got some of the big iron at Dayton and the rest from other AMers. Write if I can help (I have photos). 73, Tom W9CHP --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html The reason this message is shown is because the post was in HTML or had an attachment. Attachments are not allowed. Please post in Plain-Text only.---
Re: [AMRadio] Suggestions Please
Thanks Tom, - Original Message - From: [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Monday, July 22, 2002 5:05 PM Subject: Re: [AMRadio] Suggestions Please J- Take a look at the last few issues of Electric Radio (maybe March thru May). The big rig articles are for a rack mounted 813 by 813 am transmitter. I followed these closely and am building my own son of big rig.. (The author is helpful and answers emails.) I am using articles from the late fifties ARRL and Editors and Engineers Radio Handbooks (available on eBay). Great fun!! Also great help from AMers on this site. I got some of the big iron at Dayton and the rest from other AMers. Write if I can help (I have photos). 73, Tom W9CHP --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html The reason this message is shown is because the post was in HTML or had an attachment. Attachments are not allowed. Please post in Plain-Text only.--- ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Suggestions Please
Thanks George ! - Original Message - From: George Pritchard [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Monday, July 22, 2002 3:41 PM Subject: RE: [AMRadio] Suggestions Please The 1956 handbook has a very nice 500 watt class C all band 813 transmitter on page 198. I had that item in my hands many years ago. It was given to me by the High school I went to. I operated it and enjoyed it very much for a couple years. It also had the 811 modulators and the supplies in a rack. I did not know at that time that it was THE TRANSMITTER documented in the handbook until years later, when I found it in the 1956 handbook at a ham fest. When I opened the book and saw THAT transmitter on page 198, I almost cried! It was like looking at the gost of a long lost friend. I parted it out (kept the parts), and some of it is here and there in my 4-1000 rig, and the mod transformer is now in my DX100 (art-13 type). The final tank circuit is now my antenna tuner. Anyway... check it out. It is a beauty! Sometimes I just look at those pictures and think back when I was 16 yaers old on 11 meters with that thing (really)! My father insisted I get my license, so It was the start of my hamming. Every solder connection was right where I remembered it to be. Memories of the 813. George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Monday, July 22, 2002 3:17 PM To: amradio@mailman.qth.net Subject: Re: [AMRadio] Suggestions Please HiThere are MANY examples of single band 813 amps in the old handbooks. I have a 1963 open now, and it gives a very good explanation, pics and componant list. Also shows a power supply and control circuits. Good luck..Al/W8FAX --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html The reason this message is shown is because the post was in HTML or had an attachment. Attachments are not allowed. Please post in Plain-Text only.--- ___ 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
