[NLRS] Please educate me on N jumpers

[Dr. Gerald N. Johnson]

Center pins a little short is one possible problem. Push a finger on the 
inner ground of the male plug hard enough to leave a ring. There should 
be a dent from the center pin as deep as the ring. E. g. the center pin 
should be nearly flush with the ground tube, at least long enough to 
dent your finger as it protrudes into the ground.

Do an ohmmeter check mated to connectors, like those on the Bird. My 
suspicion is that you will find an open center conductor from a center 
pin too short. I prefer the UG-1185 connector to and of the UG-21 family 
because the center pin in the 1185 is captured by two beads and can't 
retract or be put together too short like the UG-21.

At VHF and up, some right angle connectors are poor, I'll talk on that 
at CSVHF a little bit with an SMA corner adapter as an example. I can 
show what's bad, I don't yet have a perfect solution.

Be sure to check for shorts, stray strands of shield can sneak into the 
wrong place in a connector and cause a short.

73, Jerry, K0CQ

On 7/23/2013 9:09 PM, David Palm wrote:
>
>
> Ok so I had a little misadventure this evening that seems to have turned
> out okay, but has me puzzled.
>
> I bought a 902 transverter just to get us through this upcoming contest.  I
> would prefer to deploy my W1GHZ transverter, but I'm too slow to get it
> working.  That's neither here nor there.
>
> I fired up the boughten transverter and tried to measure its power output.
> I got only a little under 3 of the advertised 10 watts and the reflected
> power was just over 2 watts.  This was into a dummy load good to 2 GHz and
> a Bird 43 meter with 5E element to measure power.
>
> Cutting to the chase, I eventually used my FT-897 and a different Bird
> element to narrow the problem down to jumpers.  I finally found a
> combination of two jumpers (one from rig to meter and one from meter to
> dummy load) that let me determine that the transverter was putting out
> close to its advertised 10 watts and then I was able to tune my WA5VJB
> "cheap yagi" for a perfect match.
>
> The consternation that I feel is that I have now a number of
> commercially-made N to N jumpers that I purchased from a guy on QTH.com,
> that I thought should be perfectly fine, that give me basically infinite
> SWR when connected in this test set-up.  Ohmed out with a DC multimeter
> they check out fine.  Can anyone give me some idea of what might be going
> wrong here and whether I should just throw these in the trash, or whether
> there could be something else going on here?  Any feedback would be
> appreciated.  This was a frustrating evening, although in the end I have
> what I want, a working transverter and a tuned antenna.
>
> Thanks and 73,
>
> David  W9HQ
>