PAL Connectors on TVs

[dkneyle]

Here in Australia the standard TV antenna has been the PAL connector since the first colour TVs were introduced in the mid-70s using 75ohm coax cable. Here we are in the 21st Century and we are still using this same connector. I'm having to write off many TVs due to failures of this input connector. It seems to fracture internally where it connects into the sealed tuner box. It seems the weight of the RG-6 cable, or an accidental pull on the antenna cable is enough to break the socket. My question to my colleagues in the USA is this: is the F-connector a more resilient connector or are you seeing the same problem?

[eccerr0r]

Re: PAL Connectors on TVs

Ahh... Now I know... the PAL/Belling-Lee connectors... I've always thought it was some weird inverse RCA phono plug...

Kind of strange though maybe not. The NTSC F-connectors tend to be attached fairly sturdily to to the tuner box, outside soldered to the shield. I think the manufacturers have been pretty diligent to strengthen it as the connector is threaded - torque on the cable goes straight to the box.

However I've noticed that the cable tends to break before the receiver box, which is good. I've seen many of the compression and crimp connectors break.

I don't work on these things that much (but enough to curse at trying to screw the connectors together! GRR... talk about frustrating!) so you may need to wait for some other opinions.

[R_J]

Re: PAL Connectors on TVs

I have repaired hundreds of F connectors broken on tuner modules, it works best if you have the original broken piece, I just solder them back in place ( I use 5% silver solder for this), being carefull with the heat as to not melt the plastic inside. Then use a thin piece of wire to connect the center conductor to the tuner board. The last one I did was quite easy as the tuner cover was easily removed. For the ones that I don't have the original F I use a F61 or one of these.
Most of the tuners I have seen have removable covers to gain access in side.

I found the pal ones here: http://www.k-sunrise.com/html_produc...nector-82.html

[dkneyle]

Thanks for your tips. My own personal TV which has got the problem is very challenging. The tuner module is in turn soldered to the mainboard in such a way as you'd need to be a microsurgeon to remove it. Popping the tuner cover doesn't give access to where the connector needs to be soldered. If I had my way I'd be converting those over to f-connectors wherever I could if it was not too hard a job. Naturally our Pay-TV operators have specified F-Connectors from day 1. It's not even as if PAL connectors are an Australian standard or anything - just convention. It would be so easy for manufacturers to just specify f-connectors and include a PAL adapter. Very quickly we'd find the transition to f-connectors had occurred. Even wall plates are PAL connectors, with f-connectors on the reverse side of the wall plate. Most TV antenna installers say the weak link is always that cheap fly lead used from the wall plate to the TV.

[stj]

Re: PAL Connectors on TVs

i replace them with F connectors salvaged from old sat tuners.

[eccerr0r]

Re: PAL Connectors on TVs

I rarely see anything other than F connectors on this "island" and I suspect people here call them the "F***ed" connector just because it's ubiquitously one of the most difficult connectors to thread together. Once they're connected, it's good: solid connection until the RG6/RG59 cable breaks. At least we know for sure that cables with F-connectors are characteristic impedance of 75Ω and good for any TV/Cable usage.

I can't say all of them are like this, but many are quite well attached to some metal frame. Can't say it's only attached by the center pin.

I'd like to see a PAL connector and how it's attached, from what I'm hearing it's not much different than F, both pretty much attached/welded/... to the case? I would imagine they should also be, for RF tightness.

[R_J]

Re: PAL Connectors on TVs

Post a picture of the main board and tuner area, You say you were able to remove the cover, so did it only show the tuner pc board? It may not be that hard to repair.

[Heihachi_73]

Re: PAL Connectors on TVs

Yes, I have had two TVs with the antenna socket ripped straight out of the back, both times was because one of our cats (the same one both times!) went behind them, tripped over everything and took the cable and socket with it, with the socket still attached to the cable.

One TV was a DSE (D¡ck Smith) 51cm/20" CRT, bought new in 2005 and wrecked by the cat a few months later, which of course wasn't covered by warranty (it still works fine as long as you only use the RCA inputs, but I haven't used it since - as with most Australian CRTs, it didn't have a SCART connector). We took it to a TV repairer and he added what he thought was a compatible RF modulator, however it was only compatible with VLF and did nothing at all on VHF/UHF, making it all but useless (the only VLF channel in Australia was the ABC, and the only other things which used it were old video game consoles such as the Atari 2600 and Sega Master System II, both of which didn't have AV out). Analog TV transmission has since been phased out so it's a moot point these days, the TV is still sitting in the garage awaiting the day someone turns it back on. Maybe one day, as the tube is almost brand new, although I remember this TV also had a really bad barrel distortion whenever anything bright was on the screen - we had actually swapped one of these the day we bought it because of the distortion but this one wasn't any better.

The other TV was a 2010 Hisense LCD which has recently died due to the caps failing and taking everything else with it (stupidly, I had already recapped it once but left in the caps that were still OK at the time, and a few years later the last of its original Samxon caps failed and killed it completely). This one was reused as a PC monitor ever since. One stupid thing about it was that despite being a 1680x1050 flat panel, it would not allow its native resolution to be used - anything beyond 1400x1050 would be truncated to 1400 wide and then stretched to fit so I basically had to force it into 4:3 mode (at least it had the option to switch between wide, which it called 16:9 despite being a 16:10 panel, and standard 4:3) and stick with a "native" pixel-perfect 1400x1050 with huge black bars either side.

In Australia, F connectors are really only used for cable TV (e.g. Foxtel) or cable internet, normal TV (whether it be the current digital TV or the former analog system) uses the regular old aerial cables with the Belling-Lee connectors.

[stj]

Re: PAL Connectors on TVs

belling-lee are the most anoying fucking RF connectors to wire i think have ever been invented - F are the simplest.
that's why i use F as a replacement. (that and having lots of sockets from analog sat boxes)

[goontron]

Re: PAL Connectors on TVs

So that's the piece of shit connector on the back of my CR-640... I assumed it was proprietary garbage and hacked up an RCA plug to fit.

[eccerr0r]

Re: PAL Connectors on TVs

Yeah, seems a lot of multi-locale radios use the Belling-Lee adapters. I could have sworn I still have one of those "nonstandard in the USA" connectors.

RCA Phonograph plugs are the other simple one...

I have a PAL analog TV Tuner card (how, don't ask...) whose tuner box has an RCA jack. It actually has an adapter to the now identified Belling-Lee connector. I've always wondered why I couldn't mate anything to that connector, plus the fact that card is a PAL tuner...

[japlytic]

Re: PAL Connectors on TVs

I've read that Belling-Lee, the inventor of this connector, has advised that this connector is only suitable for radio and not TV, and for that reason, I insist on F connectors on both sides of the wallplate, and on equipment as well.

[eccerr0r]

Re: PAL Connectors on TVs

Well FM broadcast radio and VHF-TV aren't that far apart in terms of center frequency.

Me I wish everything was 50Ω BNC... Just because my oscilloscopes use them.

I do wonder if I should get adapters to convert away even my PL-259/SO-239 which are far from "UHF".

[stj]

Re: PAL Connectors on TVs

no way any company would use bnc for permanent connections - tnc maybe.
but isnt F just perfect? the plug being just a sleeve using the wires own dielectric spacer & center conductor?

[eccerr0r]

Re: PAL Connectors on TVs

Perhaps a longing for something you don't ubiquitously have, but if you've solely been working with them, I hate mating these connectors. Aligning them sucks, takes forever to get the threads to bite. Then after one finally gets the threads to mesh is the job of twisting the connector to tighten. This surprisingly takes quite a bit of effort to twist as the connector is so small compared to the weight of the cable which puts a lot of friction on the threading surface making it harder to turn - you get very little leverage to twist together.

If the connector is out in the open, both connectors (plug and socket) are clean and shiny, and you have the perfect amount of cable slack - not too much and not too little - then it's not too bad.

Yes TNC would be easier to twist and probably mate as well. BNC is pretty nice to mate and twist - also positive feedback when you've twisted enough.