Re: [Elecraft] Coax Loss Figures
On Wed, 23 Jun 2010 11:43:30 -0500, "Phil & Debbie Salas" wrote: See below... >"...Ditch the 43 foot vertical! The 43 foot vertical craze is a joke, as >you can see by the figures, Tom, W8JI, gives you in his post showing >feedline loss and SWR" > >With a 1:4 unun at the base of the antenna, the VSWR from 40-10 meters is >not bad - resulting in minimal coax losses. However, the VSWR on 80 and 160 >meters with or without the unun is terrible, and you should match the >antenna at the base on those bands. See the "Articles" section at >www.ad5x.com for 160/80 meter matching ideas. > >Phil - AD5X But a 43 foot vertical is resonant at about 5.441MHz. That is nowhere near any ham band you could use on FD, except 6m using the tenth harmonic. Matching an antenna's feed point impedance doesn't change it's point of resonance. Any how, this thread is way off topic, since it's subject is not an Elecraft product. Those of you who want to continue this thread, let's do it with direct emails instead of the reflector. Tom, N5GE Licensed since 1976 QCWA Life Member 35102 n...@n5ge.com http://www.n5ge.com http://www.swotrc.net [snip] __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Coax Loss Figures
Actually I did one better... I found a great power point presentation and read that whole thing... Really dug being able to see the SWR plot that you had in there and that gave me a lot more confidence that I was going to be able to use my internal ATU in the K3 to get enough swing to get the job done. I'm not expecting to get much of anything below 40. I may try it but only to collect some information and write up what I find and store it away for the well in a pinch that can kinda work or don't even try... I do plan on building something similar to what you'd shown for doing 160 and 80 just to say I've built one and to make the setup that much more versatile should the need arise to get on the low bands. Looking forward to setting it up and collecting information then getting to do some comparisons between the 43 ft vertical and the Carolina windom which I'll be using together for diversity. Then I'll have one other wire up for RX only... I love having options! ;) My home station is such a compromise that the compromise situation that I get to play with on FD is just a pure joy! Not to mention that new locations also make it fun and interesting. Thanks much for all your information on the 43 ft vertical! I've found it quite informative and it gives me good information to go on to make sure things are coming out how I want. The plan is to feed it w/ 100 ft of LMR 400 or 50 ft of 9913 depending on how far away we have to put it and which gives us the best results if both are an option. ~Brett (N7MG) On Wed, Jun 23, 2010 at 9:43 AM, Phil & Debbie Salas wrote: > "...Ditch the 43 foot vertical! The 43 foot vertical craze is a joke, as > you can see by the figures, Tom, W8JI, gives you in his post showing > feedline loss and SWR" > > With a 1:4 unun at the base of the antenna, the VSWR from 40-10 meters is > not bad - resulting in minimal coax losses. However, the VSWR on 80 and 160 > meters with or without the unun is terrible, and you should match the > antenna at the base on those bands. See the "Articles" section at > www.ad5x.com for 160/80 meter matching ideas. > > Phil - AD5X > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Coax Loss Figures
"...Ditch the 43 foot vertical! The 43 foot vertical craze is a joke, as you can see by the figures, Tom, W8JI, gives you in his post showing feedline loss and SWR" With a 1:4 unun at the base of the antenna, the VSWR from 40-10 meters is not bad - resulting in minimal coax losses. However, the VSWR on 80 and 160 meters with or without the unun is terrible, and you should match the antenna at the base on those bands. See the "Articles" section at www.ad5x.com for 160/80 meter matching ideas. Phil - AD5X __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Coax Loss Figures
This is definately something I plan on trying but first I'm going to use it as intended and record results to see how they match with what I'm told and what I read... For me its not about the score its about new things to try and more data to capture and understand. I think overcoming the problems of this setup in many different ways will keep me busy for at least 5 more field days. To me that's good fun! Reminds me of the way my late grandfather was and helps me feel closer to the old man that got me into the hobby in the first place. I only wish I could still share it with him today. ~Brett (N7MG) On Jun 23, 2010 7:22 AM, "Radio Amateur N5GE" wrote: > On Wed, 23 Jun 2010 00:19:03 -0700, Brett Howard > wrote: > > Ditch the 43 foot vertical! The 43 foot vertical craze is a joke, as > you can see by the figures, Tom, W8JI, gives you in his post showing > feedline loss and SWR. > > During FD you are going to get most of your points from QSO's within > the U.S.A., so put up a 40m ground plane at eight feet on a 4X4 wooden > post in a two foot hole with 4 radials (you can use the radials to guy > the wooden post). 40m is a good band for day and night and is only 32 > feet or so tall plus eight feet of post. By doing this you will have > a resonant antenna that will cover 360 degrees at ranges within the > U.S.A. > > Adjust the length of your 43 ft vertical by removing the top ten feet > and adjusting it for the end of 40m that you are going to work or set > it in the middle of the band and attach it to the post. > > Tom, N5GE > Licensed since 1976 > QCWA Life Member 35102 > > n...@n5ge.com > http://www.n5ge.com > http://www.swotrc.net > >>Yea I know I'm going way overkill and I was doing all the calculations >>by hand of total loss and at a 7:1 SWR (which is entirely possible on >>this 43 ft vertical) the loss at 30Mhz can get kinda ugly... I've not >>modeled it fully but on all bands but on 20 meters its 7:1 and on 40 >>meters its 3:1... > [snip] > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Coax Loss Figures
On Wed, 23 Jun 2010 00:19:03 -0700, Brett Howard wrote: Ditch the 43 foot vertical! The 43 foot vertical craze is a joke, as you can see by the figures, Tom, W8JI, gives you in his post showing feedline loss and SWR. During FD you are going to get most of your points from QSO's within the U.S.A., so put up a 40m ground plane at eight feet on a 4X4 wooden post in a two foot hole with 4 radials (you can use the radials to guy the wooden post). 40m is a good band for day and night and is only 32 feet or so tall plus eight feet of post. By doing this you will have a resonant antenna that will cover 360 degrees at ranges within the U.S.A. Adjust the length of your 43 ft vertical by removing the top ten feet and adjusting it for the end of 40m that you are going to work or set it in the middle of the band and attach it to the post. Tom, N5GE Licensed since 1976 QCWA Life Member 35102 n...@n5ge.com http://www.n5ge.com http://www.swotrc.net >Yea I know I'm going way overkill and I was doing all the calculations >by hand of total loss and at a 7:1 SWR (which is entirely possible on >this 43 ft vertical) the loss at 30Mhz can get kinda ugly... I've not >modeled it fully but on all bands but on 20 meters its 7:1 and on 40 >meters its 3:1... [snip] __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Coax Loss Figures
Its called field day and I'm trying to get some of the best stuff I can... I'm having fun with it and learning more all the time. Why not help people setup their own experiences and enjoy the hobby rather than telling them that they are simply doing it wrong. If you were stuck in the woods and all you had was two pieces of wire and a K3 would you use the two together and save your life or would you never connect the two because you don't have any expensive feedline and die there? Personally I spent the money on my radio cause I was allowed to build it and learn from it. I also get better support. True diversity with equal quality receivers as I plan on using the vertical with diversity RX. I also get a UI that I am familue with and find inruitive. Last I checked using LMR400 or LMR600 for a 100 watt FD station is at least someone making an attempt. This is a hobby guys. I'm just trying to enjoy it... ~Brett. (N7MG) On Jun 23, 2010 4:21 AM, "Samuel Strongin" wrote: Let me see spend $4000.00 on a radio So you can hear better, argue over fine points in the receiver, and THEN go out and get junk cable so you can save $50.00 . I just can't see the logic. Sam kf4yox -- From: "Phil Kane" Sent: Wednesday, June 23, 2010 12:10 AM To: "Brett Howard" Cc: "elecraft" Subject: Re: [Elecraft] Coax Loss Figures > > On 6/22/2010 8:55 PM, Brett Howard wrote: > > > >> From my calculation a 5:1 mismatch on 100 feet of L... > > > __ > > Elecraft mailing list > > Home: htt... > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Coax Loss Figures
Let me see spend $4000.00 on a radio So you can hear better, argue over fine points in the receiver, and THEN go out and get junk cable so you can save $50.00 . I just can't see the logic. Sam kf4yox -- From: "Phil Kane" Sent: Wednesday, June 23, 2010 12:10 AM To: "Brett Howard" Cc: "elecraft" Subject: Re: [Elecraft] Coax Loss Figures > On 6/22/2010 8:55 PM, Brett Howard wrote: > >> From my calculation a 5:1 mismatch on 100 feet of LMR-400 would >> still get me 75watts out the antenna at 30Mhz and things only get >> better as I head down into 20 and 40 meters. > > On that basis, see if you can get some 75 ohm "hardline" from > your local cable company - they are pulling it all out in favor of > fiber optic cable and throwing it away unless the local hams > ask for it. We have several hams here who use that to go up > 70-100 foot towers and get out very well despite the apparent > mismatch. > > -- 73 de K2ASP - Phil Kane >Elecraft K2/100 s/n 5402 > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Coax Loss Figures
This reflector has more off-topic posts than any I've ever been involved with. Perhaps the solution (other than the delete key) would be for people not to reply. 73, Pete N4ZR The World Contest Station Database, updated daily at www.conteststations.com The Reverse Beacon Network at http://reversebeacon.net, blog at reversebeacon.blogspot.com, spots at telnet.reversebeacon.net, port 7000 On 6/23/2010 3:19 AM, Brett Howard wrote: > Yea I know I'm going way overkill and I was doing all the calculations > by hand of total loss and at a 7:1 SWR (which is entirely possible on > this 43 ft vertical) the loss at 30Mhz can get kinda ugly... I've not > modeled it fully but on all bands but on 20 meters its 7:1 and on 40 > meters its 3:1... > > I think I'm just going to call it a day and use the LMR400... But its > fun to overthink this stuff... Article looks nice I can see I'm going > to be up for a few more minutes! ;) > > ~Brett (N7MG) > > On Tue, 2010-06-22 at 23:34 -0700, Jim Brown wrote: > >> Check out >> >> http://audiosystemsgroup.com/Coax-Stubs.pdf >> >> 100 ft of almost any decent RG8-size or RG11-size coax is just fine for a >> Field Day antenna on the HF bands. On the lower HF bands, RG8X-size coax is >> just fine. >> >> 73, Jim K9YC >> >> >> __ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Coax Loss Figures
I was starting to look at connectors when comparing getting adapters to use the LMR600 that I have to that of using LMR400 that I have with the right connectors on it already... >From what I've seen in other models I'm expecting 7:1 SWR on 20 and 3:1 SWR on 40 with the 4:1 UNUN that DX recommends to help make things tune easier. When Elecraft makes me a remotable tuner that will work with my setup then I'm game... Till then I'll suffice with the tuner thats built into the radio. It should be able to handle most of what I should see with that 4:1UNUN on there and its capability of tuning things w/in 10:1... I'm not holding my breath for using it on 80Meters but we'll see what the tuner can handle... I plan on setting things up on Friday and taking my notebook and collecting a bunch of data on it to see how things shake out... I'm not expecting magic I'm just trying to get my head around all the math and get an idea of what I should expect so I know when to be surprised and ask questions when reality doesn't match theory... ;) ~Brett (N7MG) On Wed, 2010-06-23 at 03:15 -0400, Tom W8JI wrote: > > Well heck if LMR400 is .7dB/100ft I'm not so sure that its worth mucking > > with finding adapters for it as if I end up having to put 2 adapters on > > each end to get it to something I can use there goes most of my > > advantage of stepping up from LMR400 to LMR600... > > The loss in connectors or adaptors at HF or even up into VHF is virtually > immeasurable, unless they are simply terrible. If the connectors are > terrible you might have 0.05 dB loss. > > A common SO-239/PL259 junction has less than .02 dB loss at upper HF. > > I'd be more concerned with transmission line losses due to SWR on the > transmission line and voltage breakdown of connectors in your application. > Here are the peak voltages at the antenna base with only 100 watts applied > at the antenna, and the losses in a feedline using 100 feet of LMR500: > > 160= 4800v (>100:1 SWR) 16 dB feedline loss > 80 = 1000v (>100:1 SWR) 6 dB feedline loss > 40 = 215v (5.4:1 SWR) .6 dB feedline loss > 30 = 500v (26:1 SWR) 3 dB feedline loss > 20 = 540v (29:1 SWR) 3.5 dB feedline loss > 15 = 280v (9:1 SWR) 1.7 dB feedline loss > > Why would you worry about connectors when 100 feet of LMR500 would have > losses like that? Put a tuner at the antenna base if you want to reduce > losses. > > 73 Tom > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Coax Loss Figures
Yea I know I'm going way overkill and I was doing all the calculations by hand of total loss and at a 7:1 SWR (which is entirely possible on this 43 ft vertical) the loss at 30Mhz can get kinda ugly... I've not modeled it fully but on all bands but on 20 meters its 7:1 and on 40 meters its 3:1... I think I'm just going to call it a day and use the LMR400... But its fun to overthink this stuff... Article looks nice I can see I'm going to be up for a few more minutes! ;) ~Brett (N7MG) On Tue, 2010-06-22 at 23:34 -0700, Jim Brown wrote: > Check out > > http://audiosystemsgroup.com/Coax-Stubs.pdf > > 100 ft of almost any decent RG8-size or RG11-size coax is just fine for a > Field Day antenna on the HF bands. On the lower HF bands, RG8X-size coax is > just fine. > > 73, Jim K9YC > > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Coax Loss Figures
> Well heck if LMR400 is .7dB/100ft I'm not so sure that its worth mucking > with finding adapters for it as if I end up having to put 2 adapters on > each end to get it to something I can use there goes most of my > advantage of stepping up from LMR400 to LMR600... The loss in connectors or adaptors at HF or even up into VHF is virtually immeasurable, unless they are simply terrible. If the connectors are terrible you might have 0.05 dB loss. A common SO-239/PL259 junction has less than .02 dB loss at upper HF. I'd be more concerned with transmission line losses due to SWR on the transmission line and voltage breakdown of connectors in your application. Here are the peak voltages at the antenna base with only 100 watts applied at the antenna, and the losses in a feedline using 100 feet of LMR500: 160= 4800v (>100:1 SWR) 16 dB feedline loss 80 = 1000v (>100:1 SWR) 6 dB feedline loss 40 = 215v (5.4:1 SWR) .6 dB feedline loss 30 = 500v (26:1 SWR) 3 dB feedline loss 20 = 540v (29:1 SWR) 3.5 dB feedline loss 15 = 280v (9:1 SWR) 1.7 dB feedline loss Why would you worry about connectors when 100 feet of LMR500 would have losses like that? Put a tuner at the antenna base if you want to reduce losses. 73 Tom __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Coax Loss Figures
Check out http://audiosystemsgroup.com/Coax-Stubs.pdf 100 ft of almost any decent RG8-size or RG11-size coax is just fine for a Field Day antenna on the HF bands. On the lower HF bands, RG8X-size coax is just fine. 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Coax Loss Figures
Thats another really great data point! Knowing Cisco getting the word ultra printed on the box cost a good chunk of extra change! ;) Well heck if LMR400 is .7dB/100ft I'm not so sure that its worth mucking with finding adapters for it as if I end up having to put 2 adapters on each end to get it to something I can use there goes most of my advantage of stepping up from LMR400 to LMR600... ~Brett On Tue, 2010-06-22 at 22:19 -0600, Bob Cunnings wrote: > In Cisco parlance, "Low Loss" and "Ultra Low Loss" refers to classes > of "Aironet" coax cable assemblies. On this data sheet: > > http://tinyurl.com/yr8fck > > we find these described in Table 8. If you indeed have part nbr > "AIR-CAB100ULL-R" (where the ULL means Ultra Low Loss) then the > attenuation is specified as 4.4 dB per 100 ft at 2.4 GHz. This puts it > in the LMR600 class, < 0.5 dB attenuation per 100 ft at 30 MHz. > > Bob NW8L > > On Tue, Jun 22, 2010 at 9:16 PM, Brett Howard wrote: > > I'm trying to find the specs on this chunk of coax that has the RP-TNC > > connectors on it... I'm not having a lot of luck but perhaps someone is > > more familar with it than I... Its just says Amphenol TWO 6001 9G > > > > Then the box just says its a Cisco Systems Ultra Low Loss Coax > > Assembly... And being Cisco is why I get the joy of dealing with the > > RP-TNC... ;) But hey the whole thing was free! > > > > ~Brett > > > > __ > > Elecraft mailing list > > Home: http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/mmfaq.htm > > Post: mailto:Elecraft@mailman.qth.net > > > > This list hosted by: http://www.qsl.net > > Please help support this email list: http://www.qsl.net/donate.html > > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Coax Loss Figures
I know I'm about to sound completely nuts to everyone but I'm just doing all this stuff for FD... ;) I'll probably end up using the 100' or 50' chunk of LMR400 that I have laying around here depending on how far away the antenna has to be from the tent... Being that I'm going to be running 40 radials (and don't want to staple it down) I'm going to need to keep it away from where people will be walking. I've also got 2 other wire antennas that are proven and we know are going to work well... But I always like trying stuff that I've never done before for FD. I know we're not going to be winning any awards but I've got trees freakin everywhere and I'm going to probably have 4 antennas hooked to the K3 two RX only and two TX/RX... I've never been to the location where its held this year and so thats new for me too. I just try to have fun, make sure I get a few good bites of the potluck, and get to play with more antennas and better antennas than I'll ever have at my current home. Later I'll have a better setup but for now FD is my biggest play date w/ Ham Radio every year... These are where I get to try stupid things and find out what does and doesn't work. ~Brett (N7MG) ~Brett (N7MG) On Tue, 2010-06-22 at 21:10 -0700, Phil Kane wrote: > On that basis, see if you can get some 75 ohm "hardline" from > your local cable company - they are pulling it all out in favor of > fiber optic cable and throwing it away unless the local hams > ask for it. We have several hams here who use that to go up > 70-100 foot towers and get out very well despite the apparent > mismatch. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Coax Loss Figures
In Cisco parlance, "Low Loss" and "Ultra Low Loss" refers to classes of "Aironet" coax cable assemblies. On this data sheet: http://tinyurl.com/yr8fck we find these described in Table 8. If you indeed have part nbr "AIR-CAB100ULL-R" (where the ULL means Ultra Low Loss) then the attenuation is specified as 4.4 dB per 100 ft at 2.4 GHz. This puts it in the LMR600 class, < 0.5 dB attenuation per 100 ft at 30 MHz. Bob NW8L On Tue, Jun 22, 2010 at 9:16 PM, Brett Howard wrote: > I'm trying to find the specs on this chunk of coax that has the RP-TNC > connectors on it... I'm not having a lot of luck but perhaps someone is > more familar with it than I... Its just says Amphenol TWO 6001 9G > > Then the box just says its a Cisco Systems Ultra Low Loss Coax > Assembly... And being Cisco is why I get the joy of dealing with the > RP-TNC... ;) But hey the whole thing was free! > > ~Brett > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Coax Loss Figures
On 6/22/2010 8:55 PM, Brett Howard wrote: > From my calculation a 5:1 mismatch on 100 feet of LMR-400 would > still get me 75watts out the antenna at 30Mhz and things only get > better as I head down into 20 and 40 meters. On that basis, see if you can get some 75 ohm "hardline" from your local cable company - they are pulling it all out in favor of fiber optic cable and throwing it away unless the local hams ask for it. We have several hams here who use that to go up 70-100 foot towers and get out very well despite the apparent mismatch. -- 73 de K2ASP - Phil Kane Elecraft K2/100 s/n 5402 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Coax Loss Figures
I think I found a sheet that says its "LMR600" or at least its in a grouping that makes me think it might be LMR600. OD on the stuff is .591 by my measurements. >From my calculation a 5:1 mismatch on 100 feet of LMR-400 would still get me 75watts out the antenna at 30Mhz and things only get better as I head down into 20 and 40 meters. ~Brett (N7MG) On Tue, 2010-06-22 at 20:51 -0700, Wes Stewart wrote: > loss is meaningless. What is the diameter? > > I've been out of the industry for some time, but as I recall Amphenol > didn't make bulk cable, so they likely bought the cable from Belden, > Times, etc and built a cable assembly for Cisco. > > I think your original premise is flawed. If you want to move the > match point of a 43' vertical 100' into your shack you probably should > be looking for some 7/8" Helix. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] Coax Loss Figures
Ultra low loss is meaningless. What is the diameter? I've been out of the industry for some time, but as I recall Amphenol didn't make bulk cable, so they likely bought the cable from Belden, Times, etc and built a cable assembly for Cisco. I think your original premise is flawed. If you want to move the match point of a 43' vertical 100' into your shack you probably should be looking for some 7/8" Helix. Wes N7WS --- On Tue, 6/22/10, Brett Howard wrote: From: Brett Howard Subject: [Elecraft] Coax Loss Figures To: "elecraft" Date: Tuesday, June 22, 2010, 9:16 PM I'm trying to find the specs on this chunk of coax that has the RP-TNC connectors on it... I'm not having a lot of luck but perhaps someone is more familar with it than I... Its just says Amphenol TWO 6001 9G Then the box just says its a Cisco Systems Ultra Low Loss Coax Assembly... And being Cisco is why I get the joy of dealing with the RP-TNC... ;) But hey the whole thing was free! ~Brett __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] Coax Loss Figures
I'm trying to find the specs on this chunk of coax that has the RP-TNC connectors on it... I'm not having a lot of luck but perhaps someone is more familar with it than I... Its just says Amphenol TWO 6001 9G Then the box just says its a Cisco Systems Ultra Low Loss Coax Assembly... And being Cisco is why I get the joy of dealing with the RP-TNC... ;) But hey the whole thing was free! ~Brett __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
