| |
G8MNY > TECH 27.09.08 23:53l 63 Lines 2422 Bytes #999 (0) @ WW
BID : 3840_GB7CIP
Read: GUEST
Subj: PL259 losses
Path: IZ3LSV<IK2XDE<DB0RES<WA7V<N9ZZK<N4JOA<GB7CIP
Sent: 080927/2127Z @:GB7CIP.#32.GBR.EU #:3840 [Caterham] $:3840_GB7CIP
From: G8MNY@GB7CIP.#32.GBR.EU
To : TECH@WW
By G8MNY (New Sep 08)
(8 Bit ASCII Graphics use code page 437 or 850)
VK2AWZ wrote:-
> By the way where did the SO and PL names come from. We referred to them
> as amphenol connectors!
I have a recollection having read that the letters came from "socket" and
"plug". As regards the various numbers (SO-239/PL-259), I've no idea.
Also, ARRL, in the January 1998 issue of QST in their New Ham Companion,
The Doctor is IN; ran a "loss comparison" between the UHF and N connectors
from 1.8 up to 2000 MHz. They claimed that the loss of a UHF connector at
450 MHz was 0.09 dB compared to 0 dB for the N connector. Of course this
is dependent on the quality of both the connector and the soldering, but
anyone that can hear this difference has rather sharp ears! But seriously,
that short piece is rather interesting to read, and the results are
somewhat surprising.
73 - Jan, SM0WHH @ SL0ZS
Message timed: 10:26 on 2007-Oct-29
SOME OTHER FACTS
The 10 Amp 500V rating of the 4mm wander pin of the "UHF" PL259 connector,
properly made & used, does take some beating. The high current & voltage rating
means it is able to handle mismatch SWR, than say the tiny pins of an BNC/N
plug systems. This fact is often ignored by the purists. You have to go to the
large pin C type not N type for a better rating.
Threaded Sleeve
=========¿
Greese''' ÚÄÄÄ×ÄÄÄÄÄÄ¿_____
Thread ___³ o º ³
4mm [___³ º ³ COAX
Pin ³ o º ³
... ÀÄÄÄ×ÄÄÄÄÄÄÙ~~~~~
=========Ù Body
Moving parts like the threaded part of the sleeve & body should be greesed to
reduce wear & to mating RF kit, This also ensures a tight snug water repelant
fit (not water proof), & less chance of being cross threaded!
Typical plug impedance is 30 ohms for 15mm length. This short impedance
mismatch means the loss caused is only significant if the mismatch length is
greater than 1/12 of a wavelength, so this means loss at 70cm is only just
apparent on a properly made & used plug, & used by a few aerial makers!
Did you know you can get PL259 plugs & SO239 sockets for large low loss LDF550
coax, for things like 1km VHF radio feeder run on board large ship!
And you can even get true 50ohm versions made like the waterproof N plugs, but
at 50x the price of the cheap ones!
Why don't U send an interesting bul?
73 De John, G8MNY @ GB7CIP
Read previous mail | Read next mail
| |
