Re: [Repeater-Builder] Re: Loss through adaptors:
http://pages.cthome.net/fwc/NAV-MFG.HTM Lists some of the military codes to indicate who made an item. 73 Glenn WB4UIV At 03:15 PM 02/02/06, you wrote: I think the biggest problem that we face is that our adaptors tend to not have a pedigree. I have some that I know were from Radio Shack, some that I bought at hamfests in boxes of stuff, some with real pedigrees (amphenol, in the bag) and some that are precision test equipment in their own right. If cost were no object, we would do the whole thing in hardline and GPC-7 connectors and be done with it, right? :) Someone mentioned before, an elbow or tee that used a SPRING to make the connection.. Boy, I would love to put that on my SA and see the plot! Probably works nicely at some frequencies, and insanely badly at others. I ended up having to put at least one right angle in every radio connection. The daniels gear uses front panel N connnectors, and there's no way I could close the cabinet door without RA connectors. I couldn't find anything RA in N, so I used a single RA adaptor on each of the four lines. Not sure who makes them. Markings are CQA or CGA and UG-27/U Definitely silver plated. Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors:
--- In Repeater-Builder@yahoogroups.com, Eric Lemmon [EMAIL PROTECTED] wrote: Dave, Tessco carries right-angle N connectors from several manufacturers. Go here: http://www.tessco.com/products/displayProducts.do? groupId=410subgroupId=30 and look at pages 3 and 4. Another manufacturer of right-angle N connectors is Delta. Yes, but do they work with FSJ1-50? Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
RE: [Repeater-Builder] Re: Loss through adaptors:
Dave, About 2 yrs ago I picked up several Type-N right angle connectors made by Andrew from an eBay auction. I will look when I get home this evening to see if I have any left so I can get the part number for you. The connectors were made specifically for FSJ1-50. 73 Mike Perryman www.k5jmp.us -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] Behalf Of Dave VanHorn Sent: Friday, February 03, 2006 12:06 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Loss through adaptors: --- In Repeater-Builder@yahoogroups.com, Eric Lemmon [EMAIL PROTECTED] wrote: Dave, Tessco carries right-angle N connectors from several manufacturers. Go here: http://www.tessco.com/products/displayProducts.do? groupId=410subgroupId=30 and look at pages 3 and 4. Another manufacturer of right-angle N connectors is Delta. Yes, but do they work with FSJ1-50? Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
RE: [Repeater-Builder] Re: Loss through adaptors:
I found them on the Tessco website... here is the link.. http://www.tessco.com/products/displayProductInfo.do?sku=417130eventPage=1 73 Mike Perryman www.k5jmp.us -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] Behalf Of Mike Perryman Sent: Friday, February 03, 2006 2:04 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Re: Loss through adaptors: Dave, About 2 yrs ago I picked up several Type-N right angle connectors made by Andrew from an eBay auction. I will look when I get home this evening to see if I have any left so I can get the part number for you. The connectors were made specifically for FSJ1-50. 73 Mike Perryman www.k5jmp.us -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] Behalf Of Dave VanHorn Sent: Friday, February 03, 2006 12:06 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Loss through adaptors: --- In Repeater-Builder@yahoogroups.com, Eric Lemmon [EMAIL PROTECTED] wrote: Dave, Tessco carries right-angle N connectors from several manufacturers. Go here: http://www.tessco.com/products/displayProducts.do? groupId=410subgroupId=30 and look at pages 3 and 4. Another manufacturer of right-angle N connectors is Delta. Yes, but do they work with FSJ1-50? Yahoo! Groups Links Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors:
I think the biggest problem that we face is that our adaptors tend to not have a pedigree. I have some that I know were from Radio Shack, some that I bought at hamfests in boxes of stuff, some with real pedigrees (amphenol, in the bag) and some that are precision test equipment in their own right. If cost were no object, we would do the whole thing in hardline and GPC-7 connectors and be done with it, right? :) Someone mentioned before, an elbow or tee that used a SPRING to make the connection.. Boy, I would love to put that on my SA and see the plot! Probably works nicely at some frequencies, and insanely badly at others. I ended up having to put at least one right angle in every radio connection. The daniels gear uses front panel N connnectors, and there's no way I could close the cabinet door without RA connectors. I couldn't find anything RA in N, so I used a single RA adaptor on each of the four lines. Not sure who makes them. Markings are CQA or CGA and UG-27/U Definitely silver plated. Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
RE: [Repeater-Builder] Re: Loss through adaptors:
Dave, Tessco carries right-angle N connectors from several manufacturers. Go here: http://www.tessco.com/products/displayProducts.do?groupId=410subgroupId=30 and look at pages 3 and 4. Another manufacturer of right-angle N connectors is Delta. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Dave VanHorn Sent: Thursday, February 02, 2006 12:16 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Loss through adaptors: I think the biggest problem that we face is that our adaptors tend to not have a pedigree. I have some that I know were from Radio Shack, some that I bought at hamfests in boxes of stuff, some with real pedigrees (amphenol, in the bag) and some that are precision test equipment in their own right. If cost were no object, we would do the whole thing in hardline and GPC-7 connectors and be done with it, right? :) Someone mentioned before, an elbow or tee that used a SPRING to make the connection.. Boy, I would love to put that on my SA and see the plot! Probably works nicely at some frequencies, and insanely badly at others. I ended up having to put at least one right angle in every radio connection. The daniels gear uses front panel N connnectors, and there's no way I could close the cabinet door without RA connectors. I couldn't find anything RA in N, so I used a single RA adaptor on each of the four lines. Not sure who makes them. Markings are CQA or CGA and UG-27/U Definitely silver plated. Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors:
Keep in mind the early brown connector insulator is hydroscopic, so yes... it might act like wet toilet paper. skipp Laryn Lohman [EMAIL PROTECTED] wrote: What are they using, wet toilet paper for dielectric? Laryn K8TVZ I've seen barrel connectors with 3 db loss at 150 MHz. ron Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: Loss through adaptors:
I have issues with crimp-on connectors. I have seen too many of them pull apart when used as pigtails to tower mounted antennas.I have also seen the braid break right at the crimp. Blame it on improper crimping or the human element or whatever,but I will use the clamp style connectors. I seem to be able to get more consistent results and better mechanical strength. I agree with all the other points and will add proper weatherproofing to outside connections with vapor wrap and Scotch tape topped off with Scotchkote. 28 years with a large RCC taught me what works and what doesnt,lessons learned the hard way are not soon forgotten! 73,Lee,N3APP Eric Lemmon wrote: This topic interests me, not just because I personally abhor adaptors in any repeater system, but also because I see that others are equally passionate about certain cables. After spending many years troubleshooting repeater systems cobbled together by my friends and colleagues, most of which were replete with every connector series known to Mankind- and which used many adapters to mate between series- I became aware that the most troublesome repeaters had the largest number of adapters. When I began to design my own repeater systems, I vowed to abide by three simple rules: 1. Use only Mil-spec RG-400/U or RG-214/U cable for jumpers and interconnecting cables, and 2. Make up these cables with the correct connectors on each end, using the specified tools, and 3. Use only crimped connectors with silver-plated brass bodies, gold-plated contacts, and Teflon dielectric. None of my systems have adaptors or barrel connectors, since the cables are made up to fit the job. There are no BNC or UHF connectors; except for very unusual situations, all connectors are Type N with a few mini-UHF needed to mate with a particular radio. It would not occur to me to use an adapter to mate a male N connector to a UHF female connector- I would have a premium UHF male connector on that end of the cable! Of course, this only is an issue with older radios and duplexers; the modern counterparts have female N connectors. I guess the bottom line here is that almost all double-shielded and 100% shielded cable will perform superbly in a repeater system, if properly installed. I have never heard of any repeater system that was significantly improved by replacing RG-214/U with 3/8 hardline, Superflex, or any other trendy cable- unless the original installation was flawed. We should all be ready to accept that a flawed installation does not condemn a cable brand or type. In my personal opinion, the use of adapters in place of the exactly correct connectors leads to a flawed installation. YMMV! 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Jay Urish Sent: Monday, January 30, 2006 7:04 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Re: Loss through adaptors: Yea, I use the heck out of LMR-400UF.. Please enlighton me! Dave VanHorn wrote: For tight spots, consider superflex 1/4 or 3/8 in hard line. I actually use the mini 141 rigid line for modest power levels. FSJ1-50 now in every cable except my adaptor mess (soon to be replaced) and the 2M duplexer harness. Avoid trying to use foam center cables where possible. My FJS1-50 is foam, what's the beef with foam? Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors
I have to agree on all points. In my limited travels, I have seen a lot of questionable plating and dielectric materials showing up on all sorts of RF equipment. If its black with silver underneath, I would rather dig it out of the junk box and use it rather than going to an electronics store and taking pot luck. It took me a while to warm up to RF Specialties after having been raised on products like Dage, Sealectro, Omni Spectra, Kings and a bunch more I can't remember. On a related issue...I was on assignment at the MJ trial in central ca recently. I needed to build a short UHF duplex link from my live truck to our rented space in the coffee shop which housed our ISDN, codecs, etc. I reached into the place that should have held my spare base station antenna for such things and nothing. Where the hell was it? Makes a good case for not cleaning out the truck any more. So with the intent of building a quick quarter wave UHF ground plane, I made a quick run up to the only real electronics store (that I knew of) in Santa Maria. I ask for a type N female 4 hole connector. The guy behind the counter had to find somebody who knew what that was, then that guy had to find somebody to find them. 15 minutes later I ended up paying 9.99 a piece for 4 (all they had or ever will) ug-22 like, no name, no numbers connectors and was happy to get them. The plating looked cheap but the dielectric looked like teflon...silly me. So off to my $150 a night room at the airport Raddison and my soldering iron. Needless to say, as soon as my soldering iron hit the solder pot in the center, the dielectric started to give way. It was not teflon, it was some unknown thermo-polymer with a very low melting point! I would have been better off grinding up some corn flakes and graham crackers, mixing that with superglue and machining my own. Well, I got through it. Luckily my hop was short and if I had any duplex noise, it was covered up. My point is watch out for cheap dielectric materials! They can end up costing you a lot more than you paid for them in performance. td wb6mie Yes, I saw MJ and he looks creepier in person than he does on TV! This topic interests me, not just because I personally abhor adaptors in any repeater system, but also because I see that others are equally passionate about certain cables. After spending many years troubleshooting repeater systems cobbled together by my friends and colleagues, most of which were replete with every connector series known to Mankind- and which used many adapters to mate between series- I became aware that the most troublesome repeaters had the largest number of adapters. When I began to design my own repeater systems, I vowed to abide by three simple rules: 1. Use only Mil-spec RG-400/U or RG-214/U cable for jumpers and interconnecting cables, and 2. Make up these cables with the correct connectors on each end, using the specified tools, and 3. Use only crimped connectors with silver-plated brass bodies, gold-plated contacts, and Teflon dielectric. Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: Loss through adaptors:
Nice test results! Confirms my beliefs! Would be nice to have a list of the worst/best connectors for those not fortunate enough to have the proper test equipment. Would make a good pocket guide when hamfesting!!! 73,Lee nj902 wrote: --- In Repeater-Builder@yahoogroups.com, skipp025 [EMAIL PROTECTED] wrote: I lifted the below text from the yahoo rfamplifiers group page, posted this last week by my friend Dave. It's right on the money. http://groups.yahoo.com/group/rfamplifiers/ [paste] If you are able to measure the SWR of a coax connection at VHF, then you've installed a connector wrong. I used an HP 8510C network analyzer to measure a whole bunch of UHF to N, UHF to BNC and so forth, adapters, all stacked on top of each other to a foot long, and the lowest frequency where I measured anything of concern was at 2 GIGAhertz, where the SWR rose to 1.1:1. Yes, I know, amateur radio lore is full of the claim that UHF connectors are awful. They are, but only if you compare then to BNC and N, which are suitable for 10GHz and above. Assembled correctly, a UHF connector is invisible below 1GHz. [end] I hope nobody is buying into this BS. Connector and adapter mis-match and loss issues are hardly amateur radio lore RF manufacturers and instrumentation companies have stressed this for years - justifiably. It's easy to verify if you have access to instrumentation. Just out of curiosity I decided to run a couple of tests. When you measure a device for SWR you are actually measuring return loss. You can do this on a network analyzer or with a spectrum analyzer and tracking generator plus a signal separation device such as a return loss bridge or directional coupler. I decided to try both instruments and compare the results. You first calibrate the measurement setup with precision components from your cal kit [e.g. Agilent 85032B]. The critical component is a precision 50 ohm load. With a good bridge or coupler you should be able to measure a return loss of 40 dB or greater [equivalent to an SWR or 1.02:1] Normally your instrument test ports will be type N although some instruments have APC-7 test ports. Your cal kit should match the test ports. I started with a full 2-port cal of the VNA and a normalization of the Spectrum analyzer. My reference load did measure as expected. The next step is to insert the device under test. In this case we are interested in looking at a UHF connector. Obviously, since the instrument is type N, we have to use adapters. Just out of curiosity, I decided to compare two pairs of adapters. First an NF-NF mated to an NM-NM. [UG-57B/U and UG-29B/U] This created an insertable device. These are standard adapters as opposed to precision components and as expected, there was some degradation of the return loss measurement. I then compared this to two other adapters, NM to UHF-F and UHF-M to NF [UG-146/U and UG-83/U], again creating an insertable device This pair has just a single UHF male to female junction and results in a significant decrease in return loss [i.e. increase in SWR.] I also tried inserting an 90 degree UHF adapter [UG-646/U] in line between the UG146/U and the UG83/U which resulted in further [significant] return loss degradation. I measured several sets of these parts and the results were not only consistent from part to part but generally match within a few tenths of a dB between the VNA and the spectrum analyzer. I always like to see comparable results from two significantly different instrument setups - it confirms your thought process and results. Results at: 150 MHz, 450 MHz, 900 MHz NM-NF adapters: [VNA]: 36 dB, 35 dB, 31 dB [SA/TG] 37 dB, 35.7 dB, 30 dB N-UHF + UHF-N adapters: [VNA]: 26 dB, 16.5 dB, 11.4 dB [SA/TG]: 23.6 dB, 17.2 dB, 11.5 dB N-UHF + UHF 90 + UHF-N [VNA]: 20.2 dB, 12.03 dB, 9.3 dB [SA/TG]: 21.6 DB, 11.9 dB, 9.1 dB Now just for reference, a return loss of 11 dB would be equivalent to an SWR of 1.785 : 1 [ONE UHF junction @ 900 MHz] and a return loss of 17 dB would be an SWR of 1.329 : 1 [@ 450 MHz] UHF connectors invisible below a gigahertz??? Hardly. Also - someone asked about the 90 degree N fitting at 900 MHz so I tested a few of those. That's easy because being M on one side and F on the other, it is inherently insertable The round kind [UG-27A/U] averaged return loss of 22 dB. The square ones[UG-27D/U] are better at 27 dB [1.094 : 1 SWR] Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors:
You are right, it was a typo... the softer center foam, conductors will migrate from the center over time. Just so we are clear... the center conductor will try to migrate through the foam in sharp bends toward the outside conductor. skipp Coy Hilton [EMAIL PROTECTED] wrote: Gee Skipp, I don't remember having seen any center foam conductors before, it doesn't seem that it would work very well, especially with all of that moving around ;-) --- In Repeater-Builder@yahoogroups.com, skipp025 [EMAIL PROTECTED] wrote: In sharp bends, the softer center foam conductors will migrate from the center over time and with modest heat. Feedline/coax with soft foam centers outside in the summer sun is a serious potential trouble maker. skipp Dave VanHorn [EMAIL PROTECTED] wrote: Avoid trying to use foam center cables where possible. My FJS1-50 is foam, what's the beef with foam? Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors:
Results at: 150 MHz, 450 MHz, 900 MHz NM-NF adapters: [VNA]: 36 dB, 35 dB, 31 dB [SA/TG] 37 dB, 35.7 dB, 30 dB N-UHF + UHF-N adapters: [VNA]: 26 dB, 16.5 dB, 11.4 dB [SA/TG]: 23.6 dB, 17.2 dB, 11.5 dB N-UHF + UHF 90 + UHF-N [VNA]: 20.2 dB, 12.03 dB, 9.3 dB [SA/TG]: 21.6 DB, 11.9 dB, 9.1 dB Now just for reference, a return loss of 11 dB would be equivalent to an SWR of 1.785 : 1 [ONE UHF junction @ 900 MHz] and a return loss of 17 dB would be an SWR of 1.329 : 1 [@ 450 MHz] Ok, now what's the actual loss at those levels? I'm thinking that my intuitive rule of thumb may even be a bit light.. Better 3' of cable than one adaptor. Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors
It was not teflon, it was some unknown thermo-polymer with a very low melting point! Yeah, I've hit these too.. They look like silver plated, and the dielectric is a little pink-ish like teflon. Icky. Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors:
I sent a copy of your text examples back to Dave, and he replied with the following: [paste] He did not indicate whether he validated his calibration of the VNA, but the results suggst that the calibration was performed correctly. The SA/TG equipment should be discarded; if there's a disagreement between VNA results and SA/TG results, one would always discard the SA/TG results, because an SA/TG is not vector corrected. His statement that the precision 50 ohm load is the most important piece is not correct. The most important bit of the calibration kit is that it's been characterized in a lab that's traceable to NIST, and the measured data for that calibration kit has been loaded into the network analyzer. There is an erroneous assumption that when one connects the precision 50 ohm load and pushes cal, the analyzer measures the load, assumes it's 50 ohms, and applies a mathematical correction to itself. That's not really how it works. Instead, you first enter the calibration kit's coefficients into the VNA (usually by loading a file from a floppy disk that came with the kit), then you attach the 50 ohm load and press cal. The analyzer measures the load, then refers back to the calibration file and corrects itself so that it will measure that load as it was measured by a traceable analyzer at a lab. The load could actually be 60, 70, 80 or whatever ohms, as long as it has been accurately characterized, and the data entered into the VNA. However, the 85032 loads are good enough that at the low frequencies we're discussing, it's close enough to 50 ohms that if he doesn't bother loading the cal coefficients, he's probably not measurably in error. As I said, his measurements suggest that his cal routine was adequate. Getting fussy about having the exact cal coefficients in the instrument is only worth bothering with if you want to make return loss measurements of devices better than 40dB or above several GHz. The values he measured are consistent with some old and some poorly-assembled connectors that I have measured. RF connectors are not intended to be used and re-used more than a few hundred times; in the instrumentation industry we think of them as dispoables and keep a budget item for their replacement. The characteristics of RF connectors varies a lot by how well they're manufactured. I have seen no correlation whatsoever between price and measured performance. The stack of adapters that I measured some years ago was simply gathered. I cleaned them before measurement, and I discarded the type N connectors which had fingered ground connections that did not appear tight, as those are a well-known trouble spot. I'm not sure why anybody built type N male connectors like that, as it's a lousy way to do things. Adapters in particular, take a lot of abuse. It's good to measure these things. If you don't, then you have no idea whether you're using a good connector or a bad one. D nj902 [EMAIL PROTECTED] wrote: I hope nobody is buying into this BS. Connector and adapter mis-match and loss issues are hardly amateur radio lore RF manufacturers and instrumentation companies have stressed this for years - justifiably. It's easy to verify if you have access to instrumentation. Just out of curiosity I decided to run a couple of tests. When you measure a device for SWR you are actually measuring return loss. You can do this on a network analyzer or with a spectrum analyzer and tracking generator plus a signal separation device such as a return loss bridge or directional coupler. I decided to try both instruments and compare the results. You first calibrate the measurement setup with precision components from your cal kit [e.g. Agilent 85032B]. The critical component is a precision 50 ohm load. With a good bridge or coupler you should be able to measure a return loss of 40 dB or greater [equivalent to an SWR or 1.02:1] Normally your instrument test ports will be type N although some instruments have APC-7 test ports. Your cal kit should match the test ports. I started with a full 2-port cal of the VNA and a normalization of the Spectrum analyzer. My reference load did measure as expected. The next step is to insert the device under test. In this case we are interested in looking at a UHF connector. Obviously, since the instrument is type N, we have to use adapters. Just out of curiosity, I decided to compare two pairs of adapters. First an NF-NF mated to an NM-NM. [UG-57B/U and UG-29B/U] This created an insertable device. These are standard adapters as opposed to precision components and as expected, there was some degradation of the return loss measurement. I then compared this to two other adapters, NM to UHF-F and UHF-M to NF [UG-146/U and UG-83/U], again creating an insertable device This pair has just a single UHF male to female junction and results in a significant decrease in return loss [i.e. increase in SWR.] I
Re: [Repeater-Builder] Re: Loss through adaptors:
nj902 wrote: Connector and adapter mis-match and loss issues are hardly amateur radio lore RF manufacturers and instrumentation companies have stressed this for years - justifiably. BTW, I am told Motorola derated 'N' connectors a few years ago. They are not putting 'N' connectors on any path that carries tranmit power (not sure how much) above 800 Mhz. They are using 7/16 DIN for 800/900Mhz transmitters of late. I do know that 250W at 931 Mhz through an 'N' connector gets warm to the touch. -- Jim Barbour WD8CHL Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: Loss through adaptors:
At 1/31/2006 04:56 AM, you wrote: Nice test results! Confirms my beliefs! Would be nice to have a list of the worst/best connectors for those not fortunate enough to have the proper test equipment. Would make a good pocket guide when hamfesting!!! 73,Lee N-UHF + UHF-N adapters: [VNA]: 26 dB, 16.5 dB, 11.4 dB [SA/TG]: 23.6 dB, 17.2 dB, 11.5 dB I measured some N-UHF pairs a while back found quite a variation in return loss. The best ones had Teflon dielectric in the UHF side had a R.L. of 20 dB. The worst one had brown dielectric. Bob NO6B Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: Loss through adaptors
At 1/31/2006 11:04 AM, you wrote: It was not teflon, it was some unknown thermo-polymer with a very low melting point! Yeah, I've hit these too.. They look like silver plated, and the dielectric is a little pink-ish like teflon. Icky. Me three. PL-259 connector I bought at the Rochester Hamfest. Melted so badly that it was completely unusable. Sure looked like Teflon when I bought it. Bob NO6B Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors:
I've seen barrel connectors with 3 db loss at 150 MHz. ron What are they using, wet toilet paper for dielectric? Laryn K8TVZ Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors:
BNC connectors are constant impedaqnce connectors so are type Ns but UHF (PL259s)are not. Oh, Right angle connectors are the worse for loss. 73 AC0Y --- In Repeater-Builder@yahoogroups.com, Dave VanHorn [EMAIL PROTECTED] wrote: This one is a bit funny.. As part of the big project this weekend, I had this UHF amp with output on a pigtail with a BNC male on the end. I needed to connect with the UHF cans about 6 inches and 180 degrees of bend away, but didn't have the bits to make that cable, so I used some adaptors... Working backwards from the can: N male to PL female. PL male PL Male. PL right angle. PL female to N male. N female to PL male. PL Right angle. PL Female to BNC male. BNC female to BNC Female. What seems like pointless conversions in this chain were needed to clear the body of the cans. When testing at full power, this conglomeration of nightmares actually gets warm. The total loss through them is about 1dB though, which brings us back to the question asked last week or so about loss in adaptors.. Looks like roughly 0.2dB So, a rule of thumb emerges: Better to have three feet of good cable, than one good adaptor. Now I've made up a short BNC male to N hardline jumper, and I'm ready to go put that in place, but it will still require a BNC female- female to make the link. I'm thinking of wrapping that BNC junction in copper tape, because I don't think BNCs are all that Tight. In the future, I may just pop the covers on the amp and bring the hardlines right to the amp itself, eliminating any connectors. Thoughts on my temporary solution? Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors:
You think the adapter loss is nutty, try different kinds of good coax and rigid line to see that it also changes things quite a bit. For tight spots, consider superflex 1/4 or 3/8 in hard line. I actually use the mini 141 rigid line for modest power levels. Avoid trying to use foam center cables where possible. cheers, skipp Dave VanHorn [EMAIL PROTECTED] wrote: Thoughts on my temporary solution? This one is a bit funny.. As part of the big project this weekend, I had this UHF amp with output on a pigtail with a BNC male on the end. I needed to connect with the UHF cans about 6 inches and 180 degrees of bend away, but didn't have the bits to make that cable, so I used some adaptors... Working backwards from the can: N male to PL female. PL male PL Male. PL right angle. PL female to N male. N female to PL male. PL Right angle. PL Female to BNC male. BNC female to BNC Female. What seems like pointless conversions in this chain were needed to clear the body of the cans. When testing at full power, this conglomeration of nightmares actually gets warm. The total loss through them is about 1dB though, which brings us back to the question asked last week or so about loss in adaptors.. Looks like roughly 0.2dB So, a rule of thumb emerges: Better to have three feet of good cable, than one good adaptor. Now I've made up a short BNC male to N hardline jumper, and I'm ready to go put that in place, but it will still require a BNC female- female to make the link. I'm thinking of wrapping that BNC junction in copper tape, because I don't think BNCs are all that Tight. In the future, I may just pop the covers on the amp and bring the hardlines right to the amp itself, eliminating any connectors. Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors:
Try to find silver-plated BNC connectors. As usual, it's a mixed bag.. I have a silver F-F with even an UG number on it, but the male connectors are plated, even the one that came with the motorola amp.. I also noticed that the daniels gear all runs plated connectors, and I haven't seen them skimp on anything. But, I'm sure that the new version will be a whole lot better than what's up there now. Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors:
For tight spots, consider superflex 1/4 or 3/8 in hard line. I actually use the mini 141 rigid line for modest power levels. FSJ1-50 now in every cable except my adaptor mess (soon to be replaced) and the 2M duplexer harness. Avoid trying to use foam center cables where possible. My FJS1-50 is foam, what's the beef with foam? Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors:
In sharp bends, the softer center foam conductors will migrate from the center over time and with modest heat. Feedline/coax with soft foam centers outside in the summer sun is a serious potential trouble maker. skipp Dave VanHorn [EMAIL PROTECTED] wrote: Avoid trying to use foam center cables where possible. My FJS1-50 is foam, what's the beef with foam? Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors:
Can you also have problems with desense with fittings being hand tight between the diplexer and antenna Thank You, Ian Wells, Kerinvale Comaudio, www.kerinvalecomaudio.com.au YAHOO! GROUPS LINKS Visit your group "Repeater-Builder" on the web. To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[Repeater-Builder] Re: Loss through adaptors:
In sharp bends, the softer center foam conductors will migrate from the center over time and with modest heat. Feedline/coax with soft foam centers outside in the summer sun is a serious potential trouble maker. Define sharp. the min bend radius is 1 and none of my outside stuff is less than 12. Indoors I go down to 3 Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors:
Gee Skipp, I don't remember having seen any center foam conductors before, it doesn't seem that it would work very well, especially with all of that moving around ;-) --- In Repeater-Builder@yahoogroups.com, skipp025 [EMAIL PROTECTED] wrote: In sharp bends, the softer center foam conductors will migrate from the center over time and with modest heat. Feedline/coax with soft foam centers outside in the summer sun is a serious potential trouble maker. skipp Dave VanHorn [EMAIL PROTECTED] wrote: Avoid trying to use foam center cables where possible. My FJS1-50 is foam, what's the beef with foam? Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors:
Dave, If you have all these adapters in line feel lucky with only 1 db loss. Good adapters are sometimes hard to find unless one wants to spend some real money. The Radio Shack and most at hamfest are junk...works good on CB I guess. I've seen barrel connectors with 3 db loss at 150 MHz. ron --- In Repeater-Builder@yahoogroups.com, Dave VanHorn [EMAIL PROTECTED] wrote: This one is a bit funny.. As part of the big project this weekend, I had this UHF amp with output on a pigtail with a BNC male on the end. I needed to connect with the UHF cans about 6 inches and 180 degrees of bend away, but didn't have the bits to make that cable, so I used some adaptors... Working backwards from the can: N male to PL female. PL male PL Male. PL right angle. PL female to N male. N female to PL male. PL Right angle. PL Female to BNC male. BNC female to BNC Female. What seems like pointless conversions in this chain were needed to clear the body of the cans. When testing at full power, this conglomeration of nightmares actually gets warm. The total loss through them is about 1dB though, which brings us back to the question asked last week or so about loss in adaptors.. Looks like roughly 0.2dB So, a rule of thumb emerges: Better to have three feet of good cable, than one good adaptor. Now I've made up a short BNC male to N hardline jumper, and I'm ready to go put that in place, but it will still require a BNC female- female to make the link. I'm thinking of wrapping that BNC junction in copper tape, because I don't think BNCs are all that Tight. In the future, I may just pop the covers on the amp and bring the hardlines right to the amp itself, eliminating any connectors. Thoughts on my temporary solution? Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: Loss through adaptors:
Yea, I use the heck out of LMR-400UF.. Please enlighton me! Dave VanHorn wrote: For tight spots, consider superflex 1/4 or 3/8 in hard line. I actually use the mini 141 rigid line for modest power levels. FSJ1-50 now in every cable except my adaptor mess (soon to be replaced) and the 2M duplexer harness. Avoid trying to use foam center cables where possible. My FJS1-50 is foam, what's the beef with foam? -- Jay Urish W5GM DCARA President ARRL Life Member TXFCA President ERS Vice-Prez Denton County ARRL VEC N5ERS VP/Trustee Monitoring 1292.30Ghz PL-100.0 441.375 PL-88.5 and 444.850 PL-88.5 Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors:
--- In Repeater-Builder@yahoogroups.com, Coy Hilton [EMAIL PROTECTED] wrote: Gee Skipp, I don't remember having seen any center foam conductors before, it doesn't seem that it would work very well, especially with all of that moving around ;-) OH MY GOD! You're right!! My center foams are completely gone, and they've been replaced by a metallic copper rod! Could it be aliens? :) Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors:
I've seen barrel connectors with 3 db loss at 150 MHz. I'd replace the word barrel with the word Broken... Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors:
1. Use only Mil-spec RG-400/U or RG-214/U cable for jumpers and interconnecting cables, Well, being a ham, I'm using the FSJ1-50 because it's nicely flexible (way better than the LMR-400) and I have a ton of it on hand. 3. Use only crimped connectors with silver-plated brass bodies, gold-plated contacts, and Teflon dielectric. I had to compromise here a bit too, some are plated connectors, and all of them are soldered. I did the soldering, and I'll stand behind it. I'd use all silver connectors if I was having any luck finding them. There are no BNC or UHF connectors; Well, I have a power amp that came with BNC, and my VHF cans are UHF connectors.. What's a fella to do..? I have never heard of any repeater system that was significantly improved by replacing RG-214/U with 3/8 hardline, Superflex, or No, I'd agree there. I don't have any 214 on hand, nor connectors to use it with. I did have connectors that worked nicely with the FSJ1- 50. Once you have enough shielding, any extra is overkill. Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
RE: [Repeater-Builder] Re: Loss through adaptors:
The EIA and TIA both have a spec that virtually all cable manufacturers hold to. The static minimum bend radius of any cable that meets their spec is 10XD or ten times the diameter of the outer jacket. Under pulling load that radius doubles to 20XD. The individual manufacturer will state the maximum pulling force. I've never had any problems if I adhere to that spec. And I deal with all sorts of cabling from heliax to precision HD video coax. Rod Lane, N1FNE Senior Systems Engineer ESPN Systems Engineering -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Dave VanHorn Sent: Monday, January 30, 2006 8:02 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Loss through adaptors: In sharp bends, the softer center foam conductors will migrate from the center over time and with modest heat. Feedline/coax with soft foam centers outside in the summer sun is a serious potential trouble maker. Define sharp. the min bend radius is 1 and none of my outside stuff is less than 12. Indoors I go down to 3 Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Loss through adaptors:
--- In Repeater-Builder@yahoogroups.com, skipp025 [EMAIL PROTECTED] wrote: I lifted the below text from the yahoo rfamplifiers group page, posted this last week by my friend Dave. It's right on the money. http://groups.yahoo.com/group/rfamplifiers/ [paste] If you are able to measure the SWR of a coax connection at VHF, then you've installed a connector wrong. I used an HP 8510C network analyzer to measure a whole bunch of UHF to N, UHF to BNC and so forth, adapters, all stacked on top of each other to a foot long, and the lowest frequency where I measured anything of concern was at 2 GIGAhertz, where the SWR rose to 1.1:1. Yes, I know, amateur radio lore is full of the claim that UHF connectors are awful. They are, but only if you compare then to BNC and N, which are suitable for 10GHz and above. Assembled correctly, a UHF connector is invisible below 1GHz. [end] I hope nobody is buying into this BS. Connector and adapter mis-match and loss issues are hardly amateur radio lore RF manufacturers and instrumentation companies have stressed this for years - justifiably. It's easy to verify if you have access to instrumentation. Just out of curiosity I decided to run a couple of tests. When you measure a device for SWR you are actually measuring return loss. You can do this on a network analyzer or with a spectrum analyzer and tracking generator plus a signal separation device such as a return loss bridge or directional coupler. I decided to try both instruments and compare the results. You first calibrate the measurement setup with precision components from your cal kit [e.g. Agilent 85032B]. The critical component is a precision 50 ohm load. With a good bridge or coupler you should be able to measure a return loss of 40 dB or greater [equivalent to an SWR or 1.02:1] Normally your instrument test ports will be type N although some instruments have APC-7 test ports. Your cal kit should match the test ports. I started with a full 2-port cal of the VNA and a normalization of the Spectrum analyzer. My reference load did measure as expected. The next step is to insert the device under test. In this case we are interested in looking at a UHF connector. Obviously, since the instrument is type N, we have to use adapters. Just out of curiosity, I decided to compare two pairs of adapters. First an NF-NF mated to an NM-NM. [UG-57B/U and UG-29B/U] This created an insertable device. These are standard adapters as opposed to precision components and as expected, there was some degradation of the return loss measurement. I then compared this to two other adapters, NM to UHF-F and UHF-M to NF [UG-146/U and UG-83/U], again creating an insertable device This pair has just a single UHF male to female junction and results in a significant decrease in return loss [i.e. increase in SWR.] I also tried inserting an 90 degree UHF adapter [UG-646/U] in line between the UG146/U and the UG83/U which resulted in further [significant] return loss degradation. I measured several sets of these parts and the results were not only consistent from part to part but generally match within a few tenths of a dB between the VNA and the spectrum analyzer. I always like to see comparable results from two significantly different instrument setups - it confirms your thought process and results. Results at: 150 MHz, 450 MHz, 900 MHz NM-NF adapters: [VNA]: 36 dB, 35 dB, 31 dB [SA/TG] 37 dB, 35.7 dB, 30 dB N-UHF + UHF-N adapters: [VNA]: 26 dB, 16.5 dB, 11.4 dB [SA/TG]: 23.6 dB, 17.2 dB, 11.5 dB N-UHF + UHF 90 + UHF-N [VNA]: 20.2 dB, 12.03 dB, 9.3 dB [SA/TG]: 21.6 DB, 11.9 dB, 9.1 dB Now just for reference, a return loss of 11 dB would be equivalent to an SWR of 1.785 : 1 [ONE UHF junction @ 900 MHz] and a return loss of 17 dB would be an SWR of 1.329 : 1 [@ 450 MHz] UHF connectors invisible below a gigahertz??? Hardly. Also - someone asked about the 90 degree N fitting at 900 MHz so I tested a few of those. That's easy because being M on one side and F on the other, it is inherently insertable The round kind [UG-27A/U] averaged return loss of 22 dB. The square ones[UG-27D/U] are better at 27 dB [1.094 : 1 SWR] Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
