Ian White GM3SEK wrote in
:

Owen Duffy wrote:
Thanks Owen. BTW, what type of coax connector? Not PAL surely!

No, but they are not all that bad. Almost no one manufactured VHF land
mobiles here with UHF connectors, but they did use PAL (Belling & Lee)
once (Pye Reporters for instance).


Do Australian TVs use "Bloody Belling Lee" connectors like we still do
in the UK? What does "PAL" stand for?

Yes, the TVs invariably have the Belling Lee connector, now known as the
PAL connector. I don't know how it got the PAL label, perhaps related to
its use in the UK where PAL colour encoding was used (as it is here in
Oz). Apparently the PAL connector was invented in 1922 and complies with
BS and IEC standards.

I did some tests on BL connectors in the seventies and performance up to
2GHz was better than UHF connectors, and quite acceptable. The BL
connectors that I tested were plated brass bodied male connectors with
soldered centre pin, and plated steel bodied female connectors (all in
good condition).

Modern practice is to install F connectors in fixed wiring. There is a
range of quality in F connectors, but the Gilbert style connectors seem
reliable so long as they are done up tight with a spanner. A 'feature' of
F connectors that might mitigate against widespread adoption on
appliances.

On a related subject, the so called 'compression type' F connectors seem
to properly terminate RG6, and are available in BNC. They are a ready and
inexpensive source of weatherproof BNC termination of RG6. (Some pics at
http://www.vk1od.net/RG6/index.htm .)

Owen

Owen Duffy wrote:
Do Australian TVs use "Bloody Belling Lee" connectors like we still do
in the UK? What does "PAL" stand for?

Yes, the TVs invariably have the Belling Lee connector, now known as
the PAL connector. I don't know how it got the PAL label, perhaps
related to its use in the UK where PAL colour encoding was used (as it
is here in Oz).

OK, that makes sense.

[ Incidentally, for anyone who hasn't seen the 'alternative' meanings
for the various international color TV standards:

NTSC (USA) = Never Twice the Same Color
SECAM (France) = Something Else, Contrary to American Methods
PAL (rest of western Europe, Australia and NZ) = Perfection At Last. ]


Apparently the PAL connector was invented in 1922 and complies with BS
and IEC standards.

Or rather, the standards had to comply with the connectors, because the
connectors were there first.

I did some tests on BL connectors in the seventies and performance up
to 2GHz was better than UHF connectors, and quite acceptable. The BL
connectors that I tested were plated brass bodied male connectors with
soldered centre pin, and plated steel bodied female connectors (all in
good condition).

That's fine... now try again with the much more common aluminium bodied
plug, and a centre conductor wire that was pushed into the centre pin 20
years ago, was never soldered and is now heavily tarnished.

That unsoldered 'maybe-connection' inside the centre pin is a major
cause of poor reception and TVI in the UK... along with water in the
coax, which has an interesting effect when the water reaches the
aluminium/copper connection inside the plug body. The whole thing is a
classic example of insane design.

Modern practice is to install F connectors in fixed wiring.

Much better, as those are specifically designed to be solderless.



--

73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek