RadioBanter - View Single Post - Why does a change in jumper length change amplifer outout?

July 13th 05, 07:30 PM

wrote:
. . .
"Doubler plates" are often used in retro-fitting antennas and
other things on aircraft, just a sheet of metal to re-enforce
strength of the metal skin. The doubler plate drawings had
clearance holes just too close to type N connector sleeve
outer diameter. Connectors mated, but NOT fully. As altitude
increases, temperature drops. The not-fully mated center
conductor pin just contracted until it lost contact at cold
temps. Enlarging the doubler plate clearance hole allowed
full mating, no shrinkage of contacts. Unlikely problem
solved at about quarter to 8 PM in a cold hangar. :-(

Sometimes the "unlikely" not-described-in-text things are to
blame.

I was in Anchorage when color TV was first being broadcast there
(mid-'60s) and people were using outside antennas with coax feed for the
first time. The center pin of a male type F connector is just the center
conductor of the RG-59 cable, and on a cold day the center conductor
would shrink enough on a long cable run to pull the pin out of the
female connector.

Anybody who has spent some time as a technician (as I did) has a long
list of tales to tell about strange problems. Among my favorites are a
car with the battery installed backward (a Corvair -- car started and
ran, but gauges were funky and the radio blew), and a piece of copper
pipe with 300 ohms DC resistance. But those are just a couple. . .

Roy Lewallen, W7EL