Re: [digitalradio] A tad off-topic - Excess coax
Very little. It is a fairly broadband 1:1 transformer at HF frequencies and it forces the currents in the center conductor and shield to be equal. The amount of power lost in such a choke balun is very small compared to the power delivered to the load. See The ARRL Antenna Book 21, 26-21 73, de AA5J At 06:02 PM 10/28/2007, Dave 'Doc' Corio wrote: > Hi, Chuck. Since that is just about the exact dimension for a > "choke balun" from the original Windom design, would it have any > effect on the impedance? I suppose I could just wrap it up and see > for myself, but thought I should at least be nice enoough to > respond, since you took the time to answer my post. > >Tnx! >Dave KB3MOW > > >Chuck Mayfield wrote: >> >>If it were my station, I would wrap it around a 3 to 4 inch form and >>lay it behind the operating table. That would further limit RF noise >>and would do no harm to SWR. >> >>Best regards, >>Chuck Mayfield >> >>Neither a lofty degree of intelligence nor imagination nor both >>together go to the making of genius. Love, love, love, that is the >>soul of genius. >>~ Wolfgang Amadeus Mozart >> >>At 11:45 AM 10/28/2007, Dave wrote: >> >> >Just put up a coax-fed Windom antenna and have about 15-20 feet of >> >excess coax. I'd prefer to keep the overall length of the coax, just >> >not sure if coiling it or laying it out flat would be better. I know >> >the older Windoms needed a tight coil of coax near the antenna, but the >> >1:1 balun in this one should negate that. >> > >> >Any ideas on which might be better? >> > >> >Tnx es 73 >> >Dave >> >KB3MOW >> > >> > >> >No virus found in this incoming message. >> >Checked by AVG Free Edition. >> >Version: 7.5.503 / Virus Database: 269.15.12/1096 - Release Date: >> >10/27/2007 11:02 AM >> >> >> >> >> >>No virus found in this incoming message. >>Checked by AVG Free Edition. >>Version: 7.5.503 / Virus Database: 269.15.12/1097 - Release Date: >>10/28/2007 1:58 PM >> > >No virus found in this incoming message. >Checked by AVG Free Edition. >Version: 7.5.503 / Virus Database: 269.15.12/1096 - Release Date: >10/27/2007 11:02 AM
Re: [digitalradio] A tad off-topic - Excess coax
--- Dave 'Doc' Corio <[EMAIL PROTECTED]> wrote: > Hi, Chuck. Since that is just about the exact > dimension for a "choke > balun" from the original Windom design, would it > have any effect on the > impedance? I suppose I could just wrap it up and see > for myself, but > thought I should at least be nice enoough to > respond, since you took the > time to answer my post. > > Tnx! > Dave KB3MOW > It should not have any effect. Depending on the size of the coax (rg-8 or rg-58) I would coil it up in a 5 inch to a 1 foot in diameter coil outside the shack. If there is any RF on the outside of the coax, it will help keep it out of the shack. If there is not any rf on the outside of the coax , then it will not have any effect. __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
Re: [digitalradio] A tad off-topic - Excess coax
Hi, Chuck. Since that is just about the exact dimension for a "choke balun" from the original Windom design, would it have any effect on the impedance? I suppose I could just wrap it up and see for myself, but thought I should at least be nice enoough to respond, since you took the time to answer my post. Tnx! Dave KB3MOW Chuck Mayfield wrote: If it were my station, I would wrap it around a 3 to 4 inch form and lay it behind the operating table. That would further limit RF noise and would do no harm to SWR. Best regards, Chuck Mayfield Neither a lofty degree of intelligence nor imagination nor both together go to the making of genius. Love, love, love, that is the soul of genius. ~ Wolfgang Amadeus Mozart At 11:45 AM 10/28/2007, Dave wrote: >Just put up a coax-fed Windom antenna and have about 15-20 feet of >excess coax. I'd prefer to keep the overall length of the coax, just >not sure if coiling it or laying it out flat would be better. I know >the older Windoms needed a tight coil of coax near the antenna, but the >1:1 balun in this one should negate that. > >Any ideas on which might be better? > >Tnx es 73 >Dave >KB3MOW > > >No virus found in this incoming message. >Checked by AVG Free Edition. >Version: 7.5.503 / Virus Database: 269.15.12/1096 - Release Date: >10/27/2007 11:02 AM No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.503 / Virus Database: 269.15.12/1097 - Release Date: 10/28/2007 1:58 PM
Re: [digitalradio] A tad off-topic - Excess coax
If it were my station, I would wrap it around a 3 to 4 inch form and lay it behind the operating table. That would further limit RF noise and would do no harm to SWR. Best regards, Chuck Mayfield Neither a lofty degree of intelligence nor imagination nor both together go to the making of genius. Love, love, love, that is the soul of genius. ~ Wolfgang Amadeus Mozart At 11:45 AM 10/28/2007, Dave wrote: >Just put up a coax-fed Windom antenna and have about 15-20 feet of >excess coax. I'd prefer to keep the overall length of the coax, just >not sure if coiling it or laying it out flat would be better. I know >the older Windoms needed a tight coil of coax near the antenna, but the >1:1 balun in this one should negate that. > >Any ideas on which might be better? > >Tnx es 73 >Dave >KB3MOW > > >No virus found in this incoming message. >Checked by AVG Free Edition. >Version: 7.5.503 / Virus Database: 269.15.12/1096 - Release Date: >10/27/2007 11:02 AM
Re: [digitalradio] A tad off-topic - Excess coax
On the Encomm problem with Linux, I am not sure, but I will say that I was able to get download that fully booted on my equipment, even if it can not properly support the monitor. I did have other problems and was not able to get it to actually work and have noticed this with previous versions. I have had one Live version that had one of the PSK programs on it and it worked perfectly on the same disk, while the PSKmail programs had a sort of interruption in the audio making it useless. I have asked if anyone else had that problem and no response. Also, no response from the developers on any possible solutions. On the extra coax, I would not worry too much. The coiling near the antenna feed point (choke balun) would have been to reduce the problems the antenna has with currents flowing on the outside of the coax shield. If you already have a 1:1 choke on the antenna it may not be that significant, but coiled may be more convenient. The extra coax will lead to some increased losses in the coax, particularly on the higher bands, but probably within reason. 73, Rick, KV9U Dave wrote: > Just put up a coax-fed Windom antenna and have about 15-20 feet of > excess coax. I'd prefer to keep the overall length of the coax, just > not sure if coiling it or laying it out flat would be better. I know > the older Windoms needed a tight coil of coax near the antenna, but the > 1:1 balun in this one should negate that. > > Any ideas on which might be better? > > Tnx es 73 > Dave > KB3MOW > > > > > Announce your digital presence via our Interactive Sked Page at > http://www.obriensweb.com/drsked/drsked.php > > Yahoo! Groups Links > > > > > > >
[digitalradio] A tad off-topic - Excess coax
Just put up a coax-fed Windom antenna and have about 15-20 feet of excess coax. I'd prefer to keep the overall length of the coax, just not sure if coiling it or laying it out flat would be better. I know the older Windoms needed a tight coil of coax near the antenna, but the 1:1 balun in this one should negate that. Any ideas on which might be better? Tnx es 73 Dave KB3MOW
