N connectors are not rated for high average power, N connectors are rated for only 600 watts average power. This is a significant concern for high power JT65 transmissions on any ham band, they're less of a problem for SSB or short CW QSOs. The small diameter N connector center pin (exactly the same small center pin used in BNC connectors) heats excessively with long duration signals such as JT65 operated at power levels above about 600 watts. Heating increases center pin resistance which leads to run away heating of the center pin and catastrophic connector failure. UHF connectors are rated to at least 1500 watts average power; however, they have higher return loss (i.e., higher VSWR) than N connectors especially at 432 MHz. Inserting just a few UHF connectors in a 432 MHz transmission will have no significant system performance impact. Its difficult to observe any difference at all in s ystem performance (e.g., loss and noise figure) at 50 and 144 MHz when UHF connectors are used. Widely available DIN connectors are a much better choice at 440 MHz for high power JT65 transmissions. If N connectors must be used, keep your average power below 600 watts and use only captivated pin N connectors. Very, very few hams have the skills, training and craftsmanship to maintain the required +/- 0.020 inch center pin tolerance when installing N connectors with floating center pins used by older N connectors. 73 Frank W3LPL ----- Original Message ----- From: "Ken Arck via Moon-net" <moon-net(a)mailman.pe1itr.com> To: moon-net(a)mailman.pe1itr.com Sent: Wednesday, February 27, 2019 8:36:26 PM Subject: Re: [Moon-Net] uhf vs N connectors Contrary to popular MYTH, UHF connectors (PL-259/SO-239) aren't really all that bad at VHF. However, at the power levels used for EME, an N would be a better idea anyway Ken At 12:24 PM 2/27/2019, Robert Sauvan via Moon-net wrote: Content-Type: multipart/alternative; boundary="------------931AC885F13A1F4246F935AF" Content-Language: en-US Hi all, Still plugging away at my little pistol EME station. I was out rerouting the hardline I was planning to use for feeding my array. I discovered that I had a barrel connector splice in it so I was a bit disappointed. I dug out another piece of heliax that will now make the run without a splice. I will use the piece with the splice for my receive cable now. I assume the splice in my receive feedline will make very little difference. Im curoius how much difference there is in N connectors and the standard UHF connectors. Is it all that important as to what I should try to be using? I am more concerned with loss than I am with the ability to shed water. I have never had an issue with uhf connectors and water getting into them. My new piece of cable I had does not have any fittings on it so I will have to buy them anyway. My receive feedline, since it was used to feed a hf vertical at one point, has the standard uhf connectors. I assume I can just use it that way. As my stuff is dribbling in, Im finding that connectors on the transverter, sequencer, and the preamp have combinations of different styles of connectors as well. I think it would be wise to try to stay away from adapters as much as I can. These look to be a bit lossy I would assume. My phasing harness will have N connectors since that is what is on the baluns. I will have a number of jumpers eventually. Im just trying to get every little bit of power output as I can since Im just a little guy. Any thoughts? Thanks-Bob-W0YBS -- Thanks Bob Sauvan-W0YBS rsauvan(a)beyondbb.com http://w0ybs.com _______________________________________________ Moon-Net posting and subscription instructions are at http://www.nlsa.com/nets/moon-net-help.html ------------------------------------------------------------------------------ President and CTO - Arcom Communications Makers of repeater controllers and accessories. http://www.arcomcontrollers.com/ Authorized Dealers for Kenwood and Telewave and we offer complete repeater packages! AH6LE/R - IRLP Node 3000 http://www.irlp.net "We don't just make 'em. We use 'em!" _______________________________________________ Moon-Net posting and subscription instructions are at http://www.nlsa.com/nets/moon-net-help.html

Hello Andreas, The latest series of Commscope (formerly Andrew) captivated pin N-connectors for 7/8 inch AVA50-50 Heliax are rated at 300 0 watts average power but probably no hams use these new high power N-connectors: www.rfparts.com/connectors-heliax/connectors-78heliax/connectors-heliax-ava… But there's a problem: no mating N-connectors are available for flexible coaxial cables that are rated above 600 watts average power except perhaps the 1 KW average power rated Rosenberger connector that you use. 73 Frank W3LPL ----- Original Message ----- From: "Andreas Haefner" <dj3jj(a)gmx.net> To: donovanf(a)starpower.net, "moon-net(a)mailman.pe1itr.com" <Moon-net(a)mailman.pe1itr.com> Sent: Thursday, February 28, 2019 6:55:58 PM Subject: Re: [Moon-Net] uhf vs N connectors Hello Frank, I am sorry but your information is not correct in general that all n connectors are rated for 600 W only ! 1st power level depends on the frequency 2nd it depends on the quality of the used materials and design which depends on the knowledge of the manufacturer https://catalog.rosenberger.com/images/documents/db/53K1C7-C03N1.pdf You can see what is possible with a high performance N connector from the german Company Rosenberger For those who want to run kilowatts on frequencies up to 3 Ghz the best choice is 7/16 and more and more stations are using it. Hope this informations helps all the hams in the community who are looking for a reliable solution. With best regards and just for information and not as a criticism. Andreas DJ3JJ Gesendet mit der GMX Mail App Am 27.02.19 um 22:58 schrieb donovanf--- via Moon-net

Hello All, I can only underline Andreas' statement re the power ratings of N connectors. Properly assembled quality N connectors do well handle more than 2 kW WSJT JT65 on 2m, and this for nearly 15 years now without failure with a good friend of mine. Of course his system is well-balanced low VSWR and not in a very warm climate area. vy 73 Bernd DF2ZC www.df2zc.de ____________________________________________ 144 MHz EME NewsLetter: www.df2zc.de/newsletter twitter.com/df2zc 144 MHz DXCC #21 144 MHz WAC Kenwood TS 2000 2 x GU74b by LZ2US BEKO HLV-2000 4 x 2M18XXX 21 dBd full elevation -----Ursprüngliche Nachricht----- Von: Moon-net [mailto:moon-net-bounces@mailman.pe1itr.com] Im Auftrag von Andreas Haefner via Moon-net Gesendet: Donnerstag, 28. Februar 2019 19:56 An: donovanf(a)starpower.net; Moon-net(a)mailman.pe1itr.com Betreff: Re: [Moon-Net] uhf vs N connectors Hello Frank, I am sorry but your information is not correct in general that all n connectors are rated for 600 W only ! 1st power level depends on the frequency 2nd it depends on the quality of the used materials and design which depends on the knowledge of the manufacturer https://catalog.rosenberger.com/images/documents/db/53K1C7-C03N1.pdf You can see what is possible with a high performance N connector from the german Company Rosenberger For those who want to run kilowatts on frequencies up to 3 Ghz the best choice is 7/16 and more and more stations are using it. Hope this informations helps all the hams in the community who are looking for a reliable solution. With best regards and just for information and not as a criticism. Andreas DJ3JJ Gesendet mit der GMX Mail App Am 27.02.19 um 22:58 schrieb donovanf--- via Moon-net watts. that bad at VHF. However, at the power levels used for EME, an N would be a better idea anyway the hardline I was planning to use for feeding my array. I discovered that I had a barrel connector splice in it so I was a bit disappointed. I dug out another piece of heliax that will now make the run without a splice. I will use the piece with the splice for my receive cable now. I assume the splice in my receive feedline will make very little difference. UHF connectors. Is it all that important as to what I should try to be using? I am more concerned with loss than I am with the ability to shed water. I have never had an issue with uhf connectors and water getting into them. My new piece of cable I had does not have any fittings on it so I will have to buy them anyway. My receive feedline, since it was used to feed a hf vertical at one point, has the standard uhf connectors. I assume I can just use it that way. As my stuff is dribbling in, Im finding that connectors on the transverter, sequencer, and the preamp have combinations of different styles of connectors as well. I think it would be wise to try to stay away from adapters as much as I can. These look to be a bit lossy I would assume. My phasing harness will have N connectors since that is what is on the baluns. I will have a number of jumpers eventually. Im just trying to get every little bit o! f power output as I can since Im just a little guy. Any thoughts? _______________________________________________ http://www.nlsa.com/nets/moon-net-help.html ---------------------------------------------------------------------------- -- > President and CTO - Arcom Communications > Makers of repeater controllers and accessories. > http://www.arcomcontrollers.com/ > Authorized Dealers for Kenwood and Telewave and > we offer complete repeater packages! > AH6LE/R - IRLP Node 3000 > http://www.irlp.net > "We don't just make 'em. We use 'em!" > _______________________________________________ http://www.nlsa.com/nets/moon-net-help.html > > > _______________________________________________ http://www.nlsa.com/nets/moon-net-help.html _______________________________________________ Moon-Net posting and subscription instructions are at http://www.nlsa.com/nets/moon-net-help.html

My two cents on N-connectors: Some have been in use with my 2m-eme system since 1998. But began running 600w in 2007 and 1500w from 2010. So about nine years use at 1500w. Initially back in 2010, I forgot that I had a ten foot run of RG-213 from my 8877 to a N-barrel to a run of LMR-400 to my power meter which then connected to LMR-600/LDF7-50 to the tower. That RG-213/N-barrel broke down and melted with 1000w applied. It was an old piece of coax of unknown history so not too surprised. I replaced that run with LMR-600 using N-connectors with no further problems; N connectors hardly warm with 1500w running JT65. But the junction of my used LDF7-50 (1-5/8 inch) Heliax to LMR-600 which runs 47-foot up the tower has been problematic as the N junction is subject to movement and some stress with raising/lowering of the 2m array. I got water inside the LMR-600 which required replacing the cable & N-connector and finally replaced the old 120-foot LDF7-50, which developed high loss, with a new run of ADA7-50 (Commscope). I installed 7/16 DIN matching connectors on the two cables at that junction which has remained trouble free. But N-connectors are used with LMR cable otherwise. The M2 2mXP20 use N-female, the M2 4-way splitters use N-connectors as do my LMR-400 phasing lines and az-el wrap. LMR-600 is also used with N-connectors. My 8877 had good Teflon insulated N-female connectors as does the output of my new 1500w sspa. On 1296 I am using N-connectors (previously at 150w). New sspa will do 600w but not in service due to dish mechanical problems. The 600w amp uses sm220 cable and N-connectors which are rated higher in power. Internal coax in my new 2m 1500w amps also uses sm220 cable (a tip from Jim-W6PQL). I will use N-connectors on my 3400-MHz feed at 100w though the preamp and toshiba amps use sma. Everything at 10-GHz is either waveguide or sma. But not running QRO levels above 1296. I do agree that using good quality N-connectors and careful assembly are important for good performance, but they seem to do OK up to 1296 at high power. I have equipment at 144-MHz and below that came with UHF connectors and have done OK up to 150w. But I have a lot more troubles with them than N, BNC, TNC, or sma connectors. I only use Amphenol brand male PL-259 connectors after experiencing poor performance with "cheap stuff". I use ordinary heat shrink but add double layer of Scotch-33+ or use Scotch-Kote to seal over. I am in a very wet climate with temps to -30c to +30c (rare). Condensation is a big problem with these extremes so I usually let outside equipment breath. Of course HP amps must be air-cooled. They do heat and drive off condensation when operating. Coax relay failures : three CX-600NL and one DowKey. Former not good above 600w and DowKey was old-used. I use Narda 123sem at QRO. 73, Ed - KL7UW At 01:40 PM 2/28/2019, wa3qpx--- via Moon-net wrote: 73, Ed - KL7UW http://www.kl7uw.com Dubus-NA Business mail: dubususa(a)gmail.com

seem to have lot of use of heat shrink tube as water proofing connector since i discover silicone self fusing tape , i never again use anything else it often sold in store as plumber temporary leak fix so put 2 layer overlapping warp layer then 3M 33+ black tape for UV protection / compression this make air tight connection that very easy to remove since silicon tape stick only to itself but it elastic nature keep compression ,keep in mind that this is sold for fix water plumbing leak ! https://www.youtube.com/watch?v=Suu-6NGL93I have test it up to -40 deg and never got any water ingress Best 73! Marc VE2PN

K2RIW (SK) wrote this excellent piece years ago: Well, at least one ham thinks that UHF connectors are as good or better than N connectors at 70cm: UHF Connector Maligning -- There are many misinformed engineers and amateurs who have been led to believe that a UHF connector is the worst thing ever invented in the RF world -- due to it's lower internal impedance. They believe that each UHF connector causes a 1/2 dB insertion loss and a whole lot of VSWR at 432 MHz. I've heard quite a few amateurs claim that their 432 MHz brick amplifier will now have 1 dB greater gain since they just replaced the two chassis mounted UHF connectors with Type N connectors. This "Old Wive's Tale" has been propagated for decades. Everyone believes it. No one challenges it. Few people have ever make the measurement. A High Power "Calorimetry" Test -- Here is my observation. I took a 432 MHz Stripline Parallel Kilowatt Amplifier and applied 700 watts through a UHF female and a UHF male connector, and then into my antenna feed line. After 10 minutes of 700 watts throughput power the UHF connectors were mildly warm. If I estimate that "mildly warm" represents a dissipation of 3 watts out of 700 watts, that's an estimated insertion loss of 0.019 dB for the pair of connectors. You're about to ask, "how can this be, the internal dimensions are approximately a 35 ohm impedance, it's got to cause a 1.43:1 VSWR?" Well, it doesn't. Very Little Total System VSWR -- The mated UHF connector has an internal connector length of less than 0.9 inches. A free space wavelength at 432 MHz is 27.3 inches. The 0.9 inches represents a phase length of 11.9 degrees. If I plot this up on a Smith Chart (or use the mathematical equivalent) I find the following. A 50 ohm antenna with an 11.9 degree long section of 35 ohm line causes an input impedance of (47.9 -j7) ohms. That's an input VSWR of 1.16:1, which gives a worse case reflected-power-caused transmission loss of 0.024 dB. To me that's insignificant. Now, I'll admit that at 10 GHz, where the wavelength is 1.1 inches, that 0.9 inch electrical length connector would be much harder to tolerate. Power Tolerance -- A Type N connector can tolerate low-duty pulses of over 20 kilowatts without a voltage break down. However, steady state power of more than 1 kW could cause the connector to fail from the RF current overheating the center pin. Most connectors have a very similar failure mechanism when steady state high RF power is applied. The UHF connector has an oversized center pin that can more easily tolerate high steady state RF currents. Moreno said that 30 ohms impedance maximizes the power handling, and the UHF connector has an impedance of about 35 ohms. Each EME'er who is using those expensive type SC connectors on his kW amplifier could probably use UHF connectors for his indoor cable attachments, if he desired to save money. The UHF connector has a larger center pin than an SC connector, it might actually have a larger power tolerance than the SC -- this will require testing. But, remember that the Fluoroloy-H dielectric on the SC connector is designed to be a good heat sync that cools the center pin. It's User Friendly Assembly -- There are probably twice as many amateurs who can do a good job of installing a UHF connector on an RF cable, as compared to a Type N connector. The proper installation and WX proofing of a Type N connector requires considerable finesse and experience. It's almost an art form. UHF Connector Faults -- There are two major faults I can find with a UHF connector when it is being used on 432 and below: (1) the lack of weather proofing; (2) the lack of outer conductor finger contactors. With a proper tape wrapping job, I believe the weather proofing can be accommodated. However, the user must be sure that the internal "teeth" are properly seated, and that the outer nut is kept tight; otherwise the outer conductor can develop a considerable growth in electrical length, with the associated "scratch contacting" noise. For this reason the connector is probably inappropriate for a high vibration environment, unless an auxiliary nut-retaining mechanism is employed. So, maybe it's time we stop saying such bad things about the poor-orphaned UHF connector. For our purposes, it doesn't deserve all that flack. Properly used by a savvy engineer, who understands the idiosyncracies, it can give you a lot of bang for the dollar. It's been around for 60 years, that's no coincidence. 73 es Good VHF/UHF/SHF DX, Dick, k2RIW. ----- Original Message ----- From: "Leif Asbrink via Moon-net" <moon-net(a)mailman.pe1itr.com> To: moon-net(a)mailman.pe1itr.com Cc: "Robert Sauvan" <rsauvan(a)beyondbb.com> Sent: Wednesday, February 27, 2019 10:25:56 PM Subject: Re: [Moon-Net] uhf vs N connectors Hi Robert, A proper barrel connector would make no difference - but improper ones are not uncommon!! There is no such thing as "standard UHF connectors" I was once (about 1967) running 1kW on 70 cm. I was using RG8 with UHF connectors. The system soon failed due to a melt-down of a barrel connector. The problem was the dielectric. This one was using plexiglass - a material with very high dielectric losses. UHF connectors with teflon dielectric are very good - there are also other materials with low losses - as well as other materials with very high losses. Also BNC connectors may be bad. "Computer grade" BNC connectors have extremely lossy polyvinylchloride as the dielectric. The problem is that UHF as well as BNC have had a wide usage for other things than radio communication. Plexigalass is a good choice when one uses UHF connectors for high voltages in coaxial cables. PVC is cheaper than anything else and perfectly adequate for Ethernet... The N-connectors are difficult and to my knowledge they are used only for real radio so I do not think you could have bad luck finding N-connectors with a lossy dielectric. The N-connectors are very problematic though. A properly installed N-connector runs safely up to 6 kW and more on 144 MHz. Manufacturer specification is 1700 W only: https://literature.hubersuhner.com/Technologies/Radiofrequency/RFConnectors… The N-connectors - when brand new suffer from high contact resistance. This has been very clearly visible in my tests of noise figures on 1296 MHz as well as in measurements on intermodulation and phase noise on HF frequencies. I also lost several N-connectors in my EME system before I learned the lesson: 1) Clean the contact surfaces carefully (with polypropanol) in case the contact is not brand new. 2) Bend the ground connections outwards on the male connector to increase contact pressure. VERY IMPORTANT!!! 3) Bend the inner conductor on the female side to increase contact pressure. (less important. The chance that the original pressure is adequate is not too bad.) 4) Make sure that the inner conductor gets proper cooling. I once had a failure on my EME system because of a "professionally" mounted N-connector on a teflon cable (military surplus) The inner conductor was a little too thick to fit inside the pin so it was soldered "edge to edge" meaning that the heat transfer from the center pin was through a maybe 6 mm long thin-walled brass tube (poor thermal conductivity.) On the male side was a relay with poor performance for heat-removal. (This was before I knew about the significance of increasing the contact pressure with N-connectors.) BNC connectors have the same problems!! UHF connectors are much better provided they have a good dielectric (which many of them do not have!!!!) The contact pressure of UHF connectors is typically adequate and the contact area much larger compared to N and BNC. Make sure the rotation is correct and tighten firmly with a wrench. The UHF connector will cause an impedance mis-match. On 144 MHz and below this is insignificant. On 432 MHz it will cause a noticeable change of VSWR - and whether that is good or bad depends on your system. A single UHF connection might cause SWR to change from 1:1 to 1:1.4 or something of that order. In case that UHF connector is sitting on your PA it is totally harmless, optimum tuning would just be changed by a small amount. In case the UHF connector is on the antenna, retuning the antenna would restore perfect match. At higher frequencies, 1296 and above, the impedance change becomes a major issue so one has to be well equipped with instruments to use UHF connectors there. Presumably there is a limit somewhere when the UHF connectors become a disaster. My instruments do not go above 1.3 MHz so I do not know where the limit might be. As I see it, there is a problem in the HAM community that we look far too much for the needs in the professional world. Proffessionals need high bandwidth. Amateurs do not!!! That is why we should worry far more about ohmic/dielectric losses than mismatch losses. We can tune mismatch losses away at some particular frequency - but ohmic/dielectric losses steal power and generate thermal noise on receive. NO. Adaptors are typically not lossy at all if properly used. (Contact pressure, see above.) It is trivial for a big gun to find problems. If something gets hot you have a problem. At 1 kW, a 0.1 dB loss is 2.5% or 25W. Many things would melt - and an infrared camera - or hands on would easily show where power is lost. If you run 100 W only, a 2.5 W loss of power might not so easily be detected by its heating effects. There are other methods, measure the Q of a quarter wave cable having the connector at its open end is one way. 73 Leif _______________________________________________ Moon-Net posting and subscription instructions are at http://www.nlsa.com/nets/moon-net-help.html