[Drake] R4B antenna connector

[Glen Zook]

The inner conductor mating before the shell happens also with the UHF connectors.  The problem being "heard" in audio equipment is due to the fact that people were plugging and unplugging cables while the unit is turned on.  This is not a good practice with any kind of connector, let alone the RCA, and in certain cases this practice can cause permanent damage to the equipment.

The problem with broken insulators is not the fault of the connector but is primarily due to what people use to connect the coaxial cable to the RCA jack.  Unfortunately, way too many people use some sort of adapter and then connect that directly to RG8/U "type" or RG213/U cable.  The larger cable definitely puts a strain on the jack and the typical adapter puts even more strain on the jack.  When RG58/U cable is connected using an RCA plug then there is no strain on the connector and that is what Collins, Drake, Heath, and others, designed the equipment to use.

Also, I have run into a number of SO-239 UHF connectors with broken insulators.  Generally, this is caused by using the heavier cable and not being careful when the PL-259 is inserted into the SO-239 or by moving the cable after it has been connected.

The engineers who designed the various units used the connectors for good reasons.  Unfortunately, those engineers could not control what people "in the field" did.  Remember, at least for the Collins S-Line and KWM-2 series equipment, those were built to military specifications and the military did not have problems with the connectors.  Had there been problems, the military would have required a change.

Of course, today we can cuss or discuss the use of RCA connectors all day long since the units in question have not been manufactured for decades.  However, when the units were still in production the "problems" that we perceive today did not exist.

Glen, K9STH

Website:  http://k9sth.com


--- On Sun, 1/9/11, Jim Garland <4cx250b at muohio.edu> wrote:

Without meaning deliberately to pick a fight, there is another point of view about the RCA (phono) connector, which I share, and which is aptly described in "The Art of Electronics," by Horowitz and Hill. I quote (page 56): "The so-called phono jack used in audio equipment is a nice lesson in bad design, because the inner conductor mates before the shield when you plug it in; furthermore, the design of the connector is such that both shield and center conductor tend to make poor contact. You've undoubtedly heard the results!" I don't dispute that RCA connectors present a relatively low impedance bump in the HF region, but that is small consolation given their inherent unreliability. Even the Collins RCA jacks with the ceramic insulation are notoriously unreliable, which is one of the reasons most KWM-2s and 32S-3s these days have RF output jacks with broken and cracked ceramic. IMHO, the only worse connector is the "F" Connector used in TV sets, about
 which Horowitz and Hill say:  "Not to be outdone, the television industry has responded with its own bad standard, the type F coax "connector," which uses the unsupported inner wire of the coax as the pin of the male plug, and a shoddy arrangement to mate the shield."