BNC connectors and dodgy VHFS

[Guest]

take the old one into maplins or similar and they will sort the one you need ....

One question ... is this the plug that screws onto the antennae out socket of the radio or a bnc to bnc joint you have in the cable ? Either way - yes they can help ....

 

[mikejames]

The BNC connector is fiddly but a good connector.
When the wire fell out was the end clean and bright or did it show signs of corrosion ? If it did then you might do better replacing it wit h a waterproof connector or waterproofing the join.
The PL259 connector has the advantage that its bigger so easier to solder up. On the downside its bigger and heavier and its weight when coupled to an in-line female connector might start
making the cable break with the flexing. Hold the join down with something or use a 'bulkhead mounted' socket. ..

 

[Ships_Cat]

Yes the little male pin fits inside the hollow female one when the connectors are connected together. Should not be a problem as long as you do not get solder on the outside of the male pin or into the recieving end of the hollow female one.

I should mention that sometimes what are described as the "insulators" when assembling the plug are actually metal and the one with the spigot that slides under the braid is sometimes a conical piece that fits over the braid then the braid is teased back over the front facing conical side. But I think if you get the whole plug in front of you it will be clear as you will find that the inside dia's of all the components will exactly fit the part of the coax you slide it over if you get the assembly correct. I took the following photo of one of this style, the bits in order of assembly left to right. In this case there is a metal washer that goes between the clamp nut and pressure sleeve (the sleeve is the reddy bit) and the conical bit (the grey item) that slides over the braid and the braid then folds back over is the piece to the left of the pin. In this case the front assembly then slides on to fit up against the conical bit.

I agree with Woofy one's earlier comment that crimped connectors are better but it does not save you from the little soldering job. You do need the proper crimping tool - don't know how much a cheap one is in the UK but good cheap ones are around the equivalent of GBP15-20 here in NZ.

I would steer clear of the recommendation that the PL259's are easier to solder up. They are if you do not bother to solder the braid to the connector but that approach is a real botch up and asking for real trouble down the line for a transmitter antenna installation, especially on a boat and for safety equipment. If you solder the braid to the connector as it should be done, then I think even the experts would say that it is a very easily messed up job (Woofy's comments on melting insulation are very relevant to that too). You also need a 100 watt or so iron. One can get crimped PL259's which does save soldering the braid, but again, you need the crimping tool.

John
Photo hosted by xs.to

 

[TrueBlue]

I've read through this lot and while the replies have mostly been helpful and informative, I can't help thinking that soldering small components in situ on a moving platform is a bit much to ask the DIY'er to do.

i must be getting lazy in my old age bit I have found the solderless screw in type BNC works well for me. Strip the cable back; make lots of braid available and screw the measured cable end into the plug. The internal spring grips the signal lead tightly and the screwed outer case holds the braiding. To complete the job I use lots of self-confusing (!) tape to seal the joint. I suppose a plastic boot would be more professional and much neater.

I used to be on the fringes of ham radio and many of their aficionados swear by N-type connectors as being a better designed replacement for the PL259.

Both sorts of connectors are available from CPC/Farnell, but you do have to spend £30 to avoid carriage.

FWIW

 

[LeonF]

Thanks everyone....straight from work to Maplins this afternoon, then Thursday is the day I have a go.....just hope i didn't knacker the diodes trying to transmit without an aerial...Thanks again all.

 

[LeonF]

Nigel it's an in line connection...off to Maplins soon....still not certain about how if the female has the conductor soldered into the pin hole there is space for the male to fit in...or is there room enough??

 

[LeonF]

Thanks True.. will have a look at these as well....N-connectors..Leon

 

[Ships_Cat]

On the female pin you should find that the end that you solder the conductor into is a shallow hole whereas the other end that the male pin goes into is a deep one - the female pin is not hollow right through.

I suggest that you don't worry yourself about N connectors - they are unnecessary for the application.

John

 

[LeonF]

Thanks John...this explains it all. When trying to remake the fitting on Sunday my crew said we shouldn't try and insert the conductor into the female as it would prevent the male from entering....hence lack of contact etc etc etc. A physicist but not an electrician!!
Have been to Maplins today and bought a crimp on BNC fitting, and also a screw on BNC fitting.. both male. They don't sell them in female, but sell a double ended female connector. Have been practising this afternoon with an old piece of cable. First choice is the crimped on fitting. The pin crimped onto the conductor, then the cable inserted and the braid wrapped arounf the plug base and the sleeve crimped on...similar to a PL259. Thanks for all your help....never realised a simple task and post would get so long winded but the satisfaction in doing something like this if it succeeds is incalculable to a non -techie like myself. I sincerely believe that these little skills that contribute to self sufficiency are as important a part of seamanship as any knowledge of tides, weather etc etc. Thanks again...oh and the painful bit was the £20 the crimping tool cost !