[Elecraft] Connectors

[Jim Brown]

On 4/25/2012 4:09 PM, Alan Bloom wrote:
> P.S. Sorry, I guess I violated the Usenet rule against posting objective data...

It should be noted that in an earlier post, I noted that I had measured 
the loss of 1300 ft of coax with characteristics like LMR400 that had 
been cut into 100 ft and 200 ft lengths for a DX trip. I noted that 
there were at least 25 PL259s and 13 Amphenol barrels in line, and that 
the loss at every frequency up to 500 MHz was less than the mfr's spec 
for the cable at that frequency.  While I did not go to the extent of 
finding and measuring 1,300 ft of the same coax and subtracting out the 
loss, I submit that my measurements show that the loss in those 38 
connectors is negligible to at least 500 MHz.

And I also submit that not every small deviation from the ideal MATTERS 
in every real world conditions. Good engineering is making good choices 
for a given situation. The world does not need the $800 hammers demanded 
by certain military specs.

Shouting down?  Hardly -- when completely illogical arguments were 
presented as justification for a position I pointed them out.

Also -- I don't trust the precision of loss measurements for very small 
losses -- there are two many factors that can pollute the measurement, 
and often the accuracy of the instrumentation is a significant.fraction 
of the result being measured. For example, try getting a good number for 
the loss of 100 ft of LMR400 at 1.8 MHz. You'd better be measuring at 
least 1,000 ft to get even 10% accuracy!  Several years ago, a VE1 (RGB, 
I think) sent me data for measurements he had made of a sizable number 
of UHF connectors in a string.  His numbers for loss in a single 
connector were significantly less than what Alan has posted.

73, Jim K9YC