Choosing the the right VHF Coax

[Timccarpenter]

Originally Posted by S/V Illusion

I’ve used that solder for 60+ years on coax fittings. So far, so good

Probably a dumb question...I see some videos where a liquid flux is being applied to the connector prior to soldering. Is that needed? Are there specific types of flux I should be using?

[S/V Illusion]

Originally Posted by Timccarpenter

..I see some videos where a liquid flux is being applied to the connector prior to soldering. Is that needed? Are there specific types of flux I should be using?

Unnecessary.

[Jammer]

Tim,


The liquid flux is optional. Any flux suitable for electronics is fine, acid fluxes used for plumbing or sheet metal are not.


PL-259 connectors are difficult to solder as it is easy to either melt the dielectric, have a cold solder joint due to insufficient heat, or (paradoxically) both. That is especially true with RG-8X, with its foam dielectric and small diameter. For that you use a two-piece PL-259 (the basic PL-259 plus an adapter). Yes, you need more than 40 watts. I have a high wattage iron, I think 260 or 300 watts, that I use for them.


That said, I far prefer the DX engineering hybrid connectors that have a center solder and an outer crimp connection even though I have decades of soldering experience.

[Timccarpenter]

Originally Posted by Jammer

... I have a high wattage iron, I think 260 or 300 watts, that I use for them.

That said, I far prefer the DX engineering hybrid connectors that have a center solder and an outer crimp connection even though I have decades of soldering experience.

I purchased a 260W Weller soldering gun today. I'm hoping that will allow me to heat up the connector more quickly, flow the solder and get out. I made a complete mess of the first connector with the 40w iron and I'm sure melted the heck out of the dielectric as I had continuity between the pin and the ground after making a total mess of it. Hopefully, I'll have better success tonight.

Knowing what I do now (and buying a new solder gun), I would have gone with DX Engineering's new crimp and solder connectors.

[team karst]

So far, most of the comments relate to half of the important metric. Which is SNR, or signal to noise ratio. Yes, there is merit in Tx power, low loss coax, beam shaped antennas. But locally generated electronic noise and other on-channel intentional transmitters will degrade reception. One important task that we all should do is take a ships EMC survey. You might be surprised at what you dig up. ��.

[Jammer]

Here's an example of a good electronics flux that is, at the moment, in stock and ready to ship from our friends in Thief River Falls.


https://www.digikey.com/en/products/...LF-0-5/9558133

[Jammer]

Originally Posted by Timccarpenter

I purchased a 260W Weller soldering gun today.

Those are nice. You do have to keep the connections from the copper tip to the two conductive barrels clean, bright, and wrench tight.

Knowing what I do now (and buying a new solder gun), I would have gone with DX Engineering's new crimp and solder connectors.

[Jammer]

Originally Posted by team karst

So far, most of the comments relate to half of the important metric. Which is SNR, or signal to noise ratio. Yes, there is merit in Tx power, low loss coax, beam shaped antennas. But locally generated electronic noise and other on-channel intentional transmitters will degrade reception. One important task that we all should do is take a ships EMC survey. You might be surprised at what you dig up. ��.

At VHF, the main thing is to have an antenna installation that concentrates reception at the antenna rather than using the whole boat. Some antenna types are better at this than others, and a series choke right before the connection to the antenna can help.

[team karst]

Chokes. 😎Even DC circuits benefit sometimes.

[stormalong]

Originally Posted by team karst

Chokes. 😎Even DC circuits benefit sometimes.

Chokes are made to a frequency range -different ferrite mixes are specific to a range. Just buying a choke without knowing that frequency and not knowing what frequency you are trying to suppress gets you nowhere,

For example if you are trying to suppress alternator noise and buy a VHF choke you have not solved your problem.

The picture shows chokes with single wires through them even though there is room for more. Extra wraps multiplies their effectiveness. Just be sure that split ferrite halves are in direct contact with each other. The slightest gap nullifies the choke.

[team karst]

Trying to kill AIS interfering noise out of the Mppt’s. Those are TDK ferrites, pretty similar to FairRite mix 61. Yeah, multiple turns work if u have the wire length; i dont. Overall, prolly 80% effective on weak vhf comm freqs and ais. I havent done a good HF scan yet ( day vs nite).

[s/v Jedi]

With my $125 Weller soldering station which is 70W, soldering these is easy. With a soldering gun I struggle and prefer the crimp for outer braid with soldering center pin.

I would say that if you have never done this, the crimp type is the way to go. Also, when doing this outdoors, you need the crimp type.

Soldering this connector is the cause of about 90% of all the problems I encounter.