Soldering a pl259

Crinan12

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Lead solder, good flux and a decent iron. Remember also a small tipped iron will lose heat very quickly to a surface it it trying to also heat up. I have this on the boat Amazon.co.uk

Where are you wintering?
Hi Chris we are at lochnell, was supposed to launch yesterday but when the yard went to put the mast on they found the new backstay is too short!
Hope you and Tracey are good, will see you soon no doubt
 
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Crinan12

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I was trying to solder with the smaller pointy soldering iron tip, I will try the bigger flatter one. I don't think I've been getting the plug hot enough.

When I next replace the vhf cable I'm not going to bother with a join, will just run straight to radio.
 

bedouin

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Lead-free for plumbing, of course.
O the irony - we used to use lead pipes to plumb our houses - it wasn't that long ago I pulled a load out of this house and I think there are still a few feet of it between the street and the stopcock in our house.
 

bedouin

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I was trying to solder with the smaller pointy soldering iron tip, I will try the bigger flatter one. I don't think I've been getting the plug hot enough.

When I next replace the vhf cable I'm not going to bother with a join, will just run straight to radio.
That's probably it then - those small pointy tips are useless for anything - even for delicate electronics. Your iron may be 90W but no way can all that pass through a tiny point so no way can you get a big lump of metal like that plug hot enough with it.
 

VicS

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I was trying to solder with the smaller pointy soldering iron tip, I will try the bigger flatter one. I don't think I've been getting the plug hot enough.

When I next replace the vhf cable I'm not going to bother with a join, will just run straight to radio.
No wonder you are having trouble.
The one I would use has bit about 3/16" diameter x 1" long.

20240402_153427.jpg
Wow that's the first time I've posted an image from the phone and it worked!
 
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THE LEAD FREE SOLDER IS CRAP, lots of great advice here with 60/40 50/50 and the use of flux

The last tome i tried this on a freinds yacht,using a gas soldering iron , i could not solder it either!
 

Daverw

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I’ve moved to crimp plugs and only then solder the tip which is easy to do, getting the body hot enough away from workshop is always a challenge I find. Or as refueler says pull braid back into body and tighten well and don’t solder braid
 

LittleSister

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In my experience the typical cheap battery powered soldering iron, is v poor, almost useless. They might claim 90w but they might well not be, and poor materials/construction may well mean that the heat doesn't transfer well to the tip. Most cheap mains soldering irons are pretty lousy, too, but you can usually get away with it for light work, but those big (relatively) coax plugs are a challenge. A decent soldering iron costs money. Ideal is a temperature-controlled powerful mains powered one (usually comes with a substantial base/holder that may contain a transformer), but I doubt many of those get used for DIY boat maintenance.

Use good quality lead multicore solder. Make sure the wire and pin is as clean as possible - use meths, acetone or whatever if you don't have soldering flux to clean it.

I used to solder electronic equipment wiring for living long ago. I recommend that you do not try to melt the solder for the joint with the soldering iron - that will probably give you a poor joint, if successful at all. Heat up the joint (the pin and the wire) with the soldering iron, having first cleaned off the iron's tip and then applied a small amount of fresh multicore solder to it so it forms a modest sized convex 'dome' on the tip. This small amount of solder on the tip is purely to give better contact for heat conduction from the iron to the joint, not to form the joint itself. (Wipe this small amount of solder on the iron off frequently and apply fresh, unless the job's completed very quickly.) Place the end of the solder wire on the joint you are heating, and let the joint itself, not the iron, melt the solder. Then you are sure the joint is hot enough, and the solder should then run freely along the wire and the pin and form a good electrical contact to both.

The big challenge is getting the joint area hot enough (especially if the iron is underpowered and/or poor quality) before the heat is conducted along the pin and/or (more likely) wire and melt their insulation.

For something like a coax plug pin, it may be necessary to 'tin' the pin with solder - heat it up as above and run only just enough solder onto it to coat the relevant part of the pin. Then insert the wire (if you haven't blocked it with excess solder!) and form the joint.

Good luck.
 

Crinan12

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Thanks. I'll give this a go. I thought you melted the solder from the iron not the joint. I'll try again with some lead solder and flux.
If I don't have any luck I see you can buy solderless pl259's, a brand called Shakespeare. Presumably there is a downside to these though.
 

B27

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I'd suggest a good quality clamp/solder BNC with an adapter to PL259.
If you want the cable to last, it needs to be sealed from the damp air , let alone actual water running down the outside.



Lead solder is good.
Some of the flux advised is a bad idea, it will continue to eat the meal if you can't clean it properly after soldering. You can get 'no clean' flux in a marker pen dispenser. But cored solder should be enough.
A hot powerful iron helps, the 'solder gun ' type is a good value option, because it's quick to heat and cool, it doesn't murder tips and you can get a hot knife blade.
OTOH a pro iron is £300 with a new tip at £10 quite often.
 

MADRIGAL

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Confession time : I only solder the centre core wire - I never solder the outer ... I just make sure I uncover enough to be a really tight fit into the plug shell ...
Seems to work well enough for me, too. Thought it was just absent-minded luck the first time I forgot to solder the braid. :)
 

PaulRainbow

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I'd suggest a good quality clamp/solder BNC with an adapter to PL259.
Sorry, but that makes no sense to me. Why would you use the wrong type of connector, then use an adapter to make it the right connector ? Same amount of work to fit the BNC but two connectors to buy and an extra joint ???
 

ProDave

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Sorry, but that makes no sense to me. Why would you use the wrong type of connector, then use an adapter to make it the right connector ? Same amount of work to fit the BNC but two connectors to buy and an extra joint ???
A BNC is a FAR better designed and engineered connector, and so so much easier to fit to the cable.

And of course you need the BNC to PL259 adaptor to follow it, because radio manufacturers continue to persist us using lousy SO239 sockets on their radios that demand an equally lousy PL259 plug.

Having a BNC on the end of the cable means I can plug it into my handheld as well.
 

B27

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Sorry, but that makes no sense to me. Why would you use the wrong type of connector, then use an adapter to make it the right connector ? Same amount of work to fit the BNC but two connectors to buy and an extra joint ???
Because quality BNCs which actually seal the cable are plentiful, whereas PL259s are mostly junk only any good for use in a radio ham's bedroom.
Also the BNC is much smaller and appropriate for the cable I'm using and will go through smaller holes in the bulkhead, cable gland etc.

BNCs have a sensible size centre pin which is easy to solder with most irons, without overheating the cable.
 

PaulRainbow

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Because quality BNCs which actually seal the cable are plentiful, whereas PL259s are mostly junk only any good for use in a radio ham's bedroom.
Also the BNC is much smaller and appropriate for the cable I'm using and will go through smaller holes in the bulkhead, cable gland etc.

BNCs have a sensible size centre pin which is easy to solder with most irons, without overheating the cable.
I accept that the connector is smaller, but as for PL259s being junk, you still have to use an adapter. Never had any problems soldering PL259s
 

kwb78

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whereas PL259s are mostly junk only any good for use in a radio ham's bedroom.

Most radio hams I know pay quite good attention to the quality of their equipment and especially to antenna feeds and connectors.

The PL259 dates from pre-WW2 where it was intended for use at HF frequencies or lower, and it's perfectly sufficient for that use. For higher frequencies it's not ideal, but still acceptable for VHF. Above that they start to get more lossy and something else is a better choice. N connectors would be a better choice for marine VHF use as they have better inherent weather sealing, but for some reason the use of PL259s became established on most transceivers and so that's what we have to put up with.

If you buy decent quality connectors however, there isn't usually a problem with water ingress via the cable. For example this one has decent weather sealing. The design of the mating part of the connector is not ideal in wet environments, but you can protect against water ingress by applying silicone or dielectric grease before making the connection.
 
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