Strange things going wrong

[W7WV]

I was on the air and thought my tuner or radio had problems.
I was getting intermittent high SWR. I checked my antenna and coax and found nothing wrong. I check connections and everything was OK.
Finally I changed out a right angle coax connector that connects at my antenna switch and it fixed the problem.
This was not a Radio Shack special right angle either. It was mil spec all the way.
In all my time working on gear for the US Navy I never saw one go bad but this one sure had an intermittent short in it.
I suppose it could have been worse.

[K8ERV]

Did you check it for shorts or opens? Maybe it just got tired--

Tom K8ERV Montrose Co.

[WA9SVD]

Yes, it's unusual. But in 40+ years in Amateur Radio, I've found that NOTHING is impossible, both in the positive and the negative direction.
Sometimes even "mil spec" items can fail, whether or not there is a manufacturing defect or questionable construction.

It's really a good demonstration of Murphy. We shouldn't assume something in a system isn't a problem, no matter how good the quality, or how benign it may seem in a system; ANYTHING can fail.

Glad you found the problem, and hopefully before any damage occurred.

BTW: Right angle comnnectors have always been a bit suspect. If it's "old, old" mil surplus, it still could have been made to less than perfect construction standards; some disreputable manufacturers DID produce poor quality connectors despite the "mil spec" claim.

The big problem with the right angle connectors was that one shortcut to the manufacture was to use s flexible wire "spring" type coil to make the bend, rather than a more reliable solid conductor. The problem is that as well as introducing inductance (negligible at low HF) into the conductor, the spring wire often corroded or worse, rusted, and ultimately failed, whether it was four months or 40 years after manufacture. You may well have been victim od such a connector. Particularly with the right angle connectors, I try to get (WW II) surplus connectors made by Amphenol or Western Electric. At least those are identified as to manufacturer, and you know they WERE manufactured to mil spec. But again, eventually, any connector can fail.

[wa9cwx]

I agree, ANYTHING can go wrong, including something as non-complex as a connector, and especially if it was made to less than expected standards.

However, as so often is the case, there was more than one variable in the equation here.

Even a little corrosion, or a tiny piece of loose braid almost touching a center connector, or poor braid contact on either coax cable, all would have been disturbed as you re-connected cables. If you did this a couple times, of course that minimizes the chances of it being any thing OTHER than the angle connector, but if you only changed (moved around) things ONCE, then I would still find the whole thing suspect.

It is just that I never heard, or experienced a failure of one of these.

Just curious, did you re-check the connector, etc, to elliminate any contributing factors?

And if so, then please try to dissasemble the thing and report back.

Frank

[kb2vxa]

A $20,000 connector made by Chinese peasant labor only proves the saying "It's good enough for government work."

On the other hand Slappy Squirrel says "If it's government approved it's GOT to be good for you."

"And if so, then please try to disassemble the thing and report back."

C'mon Frank, it's sitting at the bottom of a landfill by now. http://www.qrz.com/iB_html/non-cgi/emoticons/laugh.gif

[WA9UAA]

Talk about driving you nuts, at one place where I used to work, we were running low level UHF RF into an HP analyzer and getting horrid results. In desperation one of the techs. finally found an "N" to "BNC" adapter with a 40 dB loss. Then, the guy kept it so he could stick it into other peoples setups. http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif
73,
Rob WA9UAA

[K0RGR]

Not long ago, I was hooking up an antenna for testing. The SWR seemed to be infinite. After a few choice cusswords, I found an open barrel connector.

[wa9cwx]

I just don't have enough experience with bad connectors!

I must have handled, soldered, used, owned, about One Thousand of them so far, in 45 years....But some of you guys have handled and used probably 20 or MORE thousands in electronic work, communications, etc., so you meet the few bad ones eventually!

I DO know that sloppy workmanship can make a REAL difference in performance as you approach UHF, as opposed to 80 meters ! http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif
So when soldering connectors to coax, I really take my time, and do a decent job.

[WB2WIK]

Quote[/b] (W7WV @ July 03 2007,17:17)]It was mil spec all the way.
In all my time working on gear for the US Navy I never saw one go bad but this one sure had an intermittent short in it.
I suppose it could have been worse.
"Hard pressed on my right. My center is yielding. Impossible to maneuver. Situation excellent. I am attacking."

--Ferdinand Foch-- at the Battle of the Marne

[WA9SVD]

I believe one of the corrollaries to Mr. Murphy's Law is that if an infinite number of manufacturers make an infinite number of coax connectors, the defective parts will all be bought by an Amateur Radio operator... Usually myself. http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif

[k0cmh]

"mil spec" usually includes two pieces to the document; a description of the materials used in its manufacture, and an acceptable defect level (usually taken from the old "mil spec tables"). The acceptable defect levels are stated in "parts per million units". So the military knows that everything they purchase has the possibility of X failures in every y million units purchased.

And then there is always the lot or production run where a defect "slips through" and is not detected by the quality inspection program in place (or not detected until they get into the field).

You probably got that x in y million part.

[k0dxc]

Might have been something wrong with the antenna

[WA9SVD]

Yep. Changing out an adapter indicates there's something wrong with... the antenna.

[af6de]

It's the Cattenna's fault - If ya put the coax on correctly, the fur should stand straight out from the body and a distinct MEOWing sound should be heard, if those things dont happen, then get a get Cattenna. Cattenna's can take about 1200 Watts before they explode though http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif

[KB3NDN]

Quote[/b] (KC0USZ @ July 09 2007,06:57)]Might have been something wrong with the antenna
no offence, but when you read a post - make sure you read the replies before commenting erroneously.

[N9LCD]

The contacts on ALL coaxial connectors, regardless of type, have a limited life in terms of "assemble" and "disassemble" cycles.

I had an Amphenol catalog that listed the number of cycles that a connector could be put through before the contacts deteriorated and the VSWR and loss started going up.

Those used "fest" specials may nt be such a bargin in the long run.


JERRY

N9LCD

[ai4ep]

Dern it...I knew I kept doing something all wrong .

read all posts, then answer at the bottom of last post.

does this mean I should read all posts of a 3 page thread before posting a reply ?