Labgear FM distribution unit gone noisy?

[Andrew2]

I'm another fan of the F connector. Having used Belling-Lee types for my receiving applications for many years (and suffered numerous intermittencies and failures), I changed over to F-type a few years ago. Since then my systems have been virtually 100% dependable.
They are available to fit 7mm, 5mm and smaller cables and I've found that the sockets are happy with all diameters of centre conductor. The only thing they won't do is accept a stranded centre.
By using the centre conductor as the 'pin', losses are kept low and the match preserved.
They are also very cheap as long as you stay away from Maplin.....

[G8HQP Dave]

I don't want to turn this into a connector war, but I always solder the inner of BL. I assumed it was only lazy TV aerial riggers who didn't bother to do this. Why F appeared and then became so popular is beyond me, when BNC would do the job much better.

[stevehertz]

Can someone advise what the different F type connectors are called vis a vis their 'for use with cable diameter' capabilities. From what I can see most seem to be identified by strange standard numbers etc, not (as would make it much easier) 'to fit XXmm diameter coax cable'. Thanks.

[Nuvistor]

RS components list them by the cable type number I.e. CT100, RG59 etc.

[mhennessy]

Originally Posted by G8HQP Dave

I don't want to turn this into a connector war, but I always solder the inner of BL. I assumed it was only lazy TV aerial riggers who didn't bother to do this. Why F appeared and then became so popular is beyond me, when BNC would do the job much better.

When I was a spotty teenager, I used to solder the inner. It just made sense - but then, what did I know?

Then, we got the local aerial guy in (after the 1987 storms changed reception conditions for most of us in the area) and he spent the entire time berating me for doing so. Made me feel really quite upset, thinking back. But, at no point did he explain what was actually wrong with what I'd done. I even volunteered reasons myself - such as the possibility of the solid core inner snapping if the wire was flexed too much - but I couldn't get him to expand on his beliefs. He was clearly a "jobsworth" who had been told how to do something decades previously and he'd accepted that unthinkingly.

Spool forward a couple of years and I had a Saturday job in the local electrical emporium. Through that, our paths crossed again. I was older, a tiny bit wiser - but he was just the same. He didn't remember me, so I took the chance to ask him what could possibly be wrong with soldering Belling Lee inners and it was still the same non-answer (basically, "because I say so")...

Today - more than 25 years later - that has stayed with me. If someone has an approach which I don't agree with, I really don't mind if they have a half-decent set of reasons for doing what they do - at least they've thought it through and arrived at their conclusion - and their thought-processes might cause me to think of something that I hadn't considered before. But I really struggle with the unthinking "following orders" brigade. This is engineering, not a fast-food outlet.

Today, if I have to use a Belling Lee, I often solder, but not always. Every situation is different. I've yet to have a problem with a soldered connection though...

In fairness, I wouldn't climb on a roof back then, and I wouldn't do it today. We're all different

[Herald1360]

Originally Posted by rambo1152

Some people advocate soldering the inner of a BL plug. The fact that it is probably a good idea for those who can carry it out without melting the insulator or cable dielectric only serves to reinforce my belief that they are not now fit for purpose, so I would advocate only using them when there is no alternative ie at the final connection to the radio or TV set itself.

I thought it was only cowboys and others looking for return chargeable visits who didn't solder the inner on BL plugs. It's not difficult, just ensure it's all clean and do it quickly after the plug is assembled onto the cable with a suitable stickout on the inner.

The ones that really aren't fit for purpose are the crappy screw termination jobs with prestripped threads!

[mhennessy]

Originally Posted by stevehertz

Can someone advise what the different F type connectors are called vis a vis their 'for use with cable diameter' capabilities. From what I can see most seem to be identified by strange standard numbers etc, not (as would make it much easier) 'to fit XXmm diameter coax cable'. Thanks.

See here for plugs vs cable diameter: http://www.satcure.co.uk/accs/page7.htm#fconn

BTW, if you have several to do, I really recommend TL04780 - it saves a lot of wear and tear on your fingers, and doesn't cost much

[ms660]

Used to have a clip on heat sink for soldering BL inner when I was a TV tech, similar heat sink for soldering the old geranium tranziter leads as well.

Lawrence.

[G6Tanuki]

I've seen BL plugs with the centre-pin made of aluminium! Definitely not solder-friendly.

To be honest at first I saw the F-connector as a horrible cheapskate device, lacking a 'proper' centre-pin. Then I ran a few tests using a lab-grade reflectometer and saw that they were *way* better at preserving constancy of impedance than BL ones, particularly above 500MHz.

Colour me enlightened!

[Philips210]

Hi.

I was taught from an early age to solder the inner of the BL plugs. Cheap, grotty plugs were a problem and usually the sleeve was corroded making soldering difficult. I used to run a narrow angle scalpal blade around the inside of the sleeve where it was to be soldered.

I quite like the F connectors and found this type of connection system to be very reliable. They're also quicker to install than BL plugs.

Regards
Symon.

[Biggles]

I have come round to preferring the F connectors as opposed to BL types. At least they don't work loose from the socket. I once was advised by an aerial installer to tighten them with a 10mm spanner. I don't. never had problems with F connectors and they seem to be the industry standard now on things like mast head amps. Less number of parts to drop from a roof top than the BL types. I never solder BL types and have never had problems with bad connections, only the whole plug being pulled out of the socket on the back of the TV. They can be quite a loose fit.
Alan.

[stevehertz]

Originally Posted by mhennessy

See here for plugs vs cable diameter: http://www.satcure.co.uk/accs/page7.htm#fconn

That page shows three (allegedly different) F connector types each identified as narrow, medium and wide, yet all "for use with 7mm cable"? That can't be right surely? It's confused me anyway, what's going on?

[mhennessy]

You might need to scroll down ever so slightly

[stevehertz]

Mark I've seen the 5mm one below those? But my previous question/confusion is still valid?! (3 different connectors: one cable size, why?)

[mhennessy]

It's all explained on the website. TL; DR: the cable types vary in their construction, and while you'd succeed in making any of the 7mm types fit a 7mm cable, it's best to pick the right plug for the cable you have.