The designations even sound like Military/Navy. I'm guessing it was in the WWI era or shortly thereafter...
Not true, some aviation and commercial gear use UHF connectors. Some new equipment has a fancy "Mini UHF" connector! Why they don't switch to BNC/TNC or other connectors eludes me, as I transition most equipment to those connectors when I can.
Unfortunately, this is true. I have never seen UHF connectors on modern aviation equipment, but a lot of maritime equipment aimed to both pleasure and professional craft market segment use the UHF connector. This is justified from the manufacturers by the sheer number of users around, and that it is a connector you can get hold of even i third-world countries. As one who writes specifications for radio installations onboard both civilian and naval vessels, it very much annoys me that the marine radio manufacturers do not want to supply quality connectors, even as an option. 73/ Karl-Arne SM0AOM
Yes, modern general aviation or commercial aircraft equipment is not equipped with the UHF, but ground support radios are. Thanks to the FAA and other organizations, the UHF is not favored in aircraft anymore. However, I still find RCA connectors being used for transponder cavity output connectors! Hopefully, with solid state output transponders, that will end as well.
The characteristic impedance of transmission lines depends on separation, width, dielectric. If you just solder coax pieces together, you MAY do it neatly enough and precisely enough --as you did--to achieve close to a 50 ohm impedance, but the amount of effort that would take is seldom part of the 'ham' repertoire. I've seen too many soldered (together)pieces of coax in a dog-leg arrangement where the ham was then perplexed why the coax was radiating, for example.
I should have said that "currently manufactured" commercial equipment, excluding CB and Ham, has transitioned away from the UHF connector. Motorola has been using the "Mini-UHF" connector for quite a while on it's VHF - UHF mobile radios. The Mini-UHF connector actually has very good electrical performance into the Gigahertz (!) range, but it suffers the same mechanical mating deficiencies of the "standard" UHF connector, namely that the shield connection is entirely dependant on the torque of the tightening collar which is not a good idea for mobile equipment. I agree on the switch to BNC/TNC, I favor the TNC because its tighter mechanical mating is better in a mobile environment.
I agree, manufacturers still use UHF connectors because "everybody else uses them". The first manufacturer to use a quality connector would suffer a loss of sales because people are resistant to change, they want to keep on using what they have been using, no matter how bad it is.
Hey Jim. Thanks for this, never made that measure my self, but now have your measurements for documentation. rgds Lars oz1fjb / ou2v
A related problem to a universal change to the series of connectors is that many have lash-up cables ready to use where needed plus some long coaxes have the PL-259 or some "N" connector already on the cable. To make a change would mean either changing the connector or using an adapter. I'd guess most would rather have adapters and this would allow the "other" connector to be used in some later application plus it's a lot faster and means less effort. I can see some who would rather use the PL-259/SO-239 systems merely because that's what they are accustomed to using. Those who prefer the change are those who like the improvement in either impedance matching or inherent sturdiness acquired in the connector change. Also, the impedance variations when using an adapter, although small, does add to the system losses and this alone would meed resistance by the user/s. Pros and Cons... For me, I still prefer the UHF connector and have always changed the Heathkit use of the Motorola connector to a SO-239. The Motorola connector is cheap and dirty but when you have one radio using it and all the others using UHF connectors, it seemed less than professional even though it is a personal preference. Add to that the fact that the available Motorola connectors today are usually crimped on some audio cable, the inability to change the cable to RG-58, for example, is not a "plug-n-chug" situation. When you get the RF cable on some Heathkit and the power supply uses the same connector, it's time for a change. Some of the early QRP kits had this. We've come too far in radio electronics to rush into a change where the change is not, overall, very practical or economical. I'd rather see change and improvement in areas where it is more tangible.
But I think the UHF connector is just not that "bad". So, manufacturers will be unwilling to change to something else that is just not clearly superior in most ways. I think the TNC connector is the way to go, at least on LMR equipment. But at frequencies below 450MHz or so, there just isn't a real clear advantage, when all things are considered. In my experience, I have had more problems with mechanical problems with mini-UHF connectors (percentage wise) than their big brothers. I just don't see anyone gaining a huge advantage, or even a small one, by switching connectors used on equipment that operates at VHF or lower frequencies. Probably equivalent to shortening the feedline by 5 inches, just won't be seen.
Attitudes like this are EXACTLY why manufacturers still use UHF connectors on ham equipment. They don't want to hear the whining and crying from people who want to keep on using what they are used to using, people who make excuses like "it's not that bad", or "it's good enough".
But the truth is that it isn't that bad, and it is good enough. If no noticeable improvement can be had, why change things? And it's not just ham equipment. It is almost all LMR mobile equipment used on VHF, and a lot of it used on UHF. The truth is, there is really nothing wrong with the connectors when used at these frequencies, and at power levels up to 100 watts or more. Up to more than 1500 watts at HF.
By your own admission in your post #41, the mechanical mating of the UHF and Mini-UHF connectors IS INFERIOR to the other connectors (TNC) that YOU prefer. To quote W1YW in post #5 "The problem arises when they loosen and/or oxidize (which is inevitable). Then you --may--suffer from intermod, which can raise the noise floor". The other problem with the UHF series is its total lack of weather resistance. I think that noticeable improvement can be made, and this is enough reason to change things. BOTH of these problems are solved by N connectors and they are good to at least 12 GHz. Wouldn't it be nice if ALL ham gear used one type of RF connector that would have a constant impedance and minimal loss at ALL frequencies, and would be weather resistant when used in outdoor applications like fixed station or mobile antennas? Wouldn't it be nice if we didn't have to worry about the number of connectors in our antenna feed systems because they have a constant 50 ohm impedance and mechanically and electrically reliable contacts that don't rely on the torque of the locking ring? How about a connector for which you don't have to make excuses?
The PL-259 connector is fine when properly crimped or soldered by a well trained installer. Some of my soldered ones, (indoor or out) are well on their way to 40 years in use. Silver plated BNC's are at the top of my list for intermittents. Heath used the RCA type on the SB-200 input and is the first thing I toss in favor for a SO-239 or "good" BNC. Carl
