RF choking

[W5LZ]

Water in coax causes an impedance change in that coax and will eventually destroy it from corrosion.
There are a number of sealants for coax connectors. They range from stuff you squirt inside the connectors, to stuff you put on the outside of them. The only thing to remember about sealing a connector is that eventually you will want to un-seal them too, so don't make that seal permanent. You also want to use something that will not damage whatever it comes into contact with, and that isn't conductive. After that, it's more or less whatever you happen to have, or can get.
- 'Doc

(Flour and water paste will work, but things like to eat it so it isn't a real good choice.)

 

[delta]

For a good watertight seal on antenna conections i always use Self-Amalgamating Tape it's easy to use and it comes off easy too.

It says on the packet

A very useful derivative of insulating tape which can be used for waterproofing connections. To use, the top protective layer is peeled off and the rubbery self- amalgamating tape underneath is wrapped tightly around the connection to be waterproofed. Eventually, the layers of this tape will merge together and create a waterproof seal. This tape is highly recommended for automotive work and also aerial installations, particularly those for satellite TV where cables enter the LNB and polariser.

 

[loosecannon]

here is a link to someone installing a PL259:

YouTube - PL-259 Installation Made Easy for RG213

i dont like the way he strips the cable, but the way he solders it is good.

the thing to remember when soldering the connector to the shield is; once the solder is hot enough, it WILL melt.

people tend to get impatient when doing this and never get the thing hot enough.

i run my HAKO soldering iron at about 890* F for soldering connectors, and i usually have to warm the connector for 10-20 seconds before solder will start to melt into the holes.

that is just for reference.

good luck,
LC

 

[357]

Ok I'm about to climb my tree and add the choke,
is the choke ok?
It is measured Pi x mhz =11.78-12.10 feet, I got 11'11" tip to tip.

4" coils x 6

Is this good?


Thanks.

also i seen this on soldering pl259.

http://www.seed-solutions.com/gregordy/Amateur Radio/Experimentation/SolderCoax.htm

 

[freecell]

a 2 liter bottle* makes a good winding form. 6 - 7 turns at about a 5" diameter* is good, the important thing is to find a way to keep the turns as close to the same diameter as possible and keep them tightly side-by-side as much as possible for best performance.

 

[357]

well I installed the choke, made ZERO difference.

http://www.youtube.com/watch?v=ubocKqRSXfc

 

[freecell]

exactly what "changes" were you wanting to see?

 

[Beetle]

LC - I can't seem to reply directly to your post about soldering so I'll cut and paste here -- hope it works.
--------------------
i dont like the way he strips the cable, but the way he solders it is good.

>> I have to disagree. He's using about a 25 watt iron .. maybe as much as 40 watts. Too small.
----------------------------------

the thing to remember when soldering the connector to the shield is; once the solder is hot enough, it WILL melt.

>> Yes it will. And if you get the dielectric hot enough, it will deform, if not actually melt.

people tend to get impatient when doing this and never get the thing hot enough.

>> With that low wattage iron and tiny tip, the connector will never get hot enough in the area you're concerned with until the entire mass of coax inside it is literally at the same temperature as the connector.
--------------------------------------------

i run my HAKO soldering iron at about 890* F for soldering connectors, and i usually have to warm the connector for 10-20 seconds before solder will start to melt into the holes.

>> Whether it's a HAKKO, Weller, Craftsman or whatever brand, the physics remains the same. Exact tip temperature doesn't matter. What matters first is the mass of the tip. A tiny chisel tip such as we see in that Ten-Tec video will drop from 900 degrees to room temperature in a heartbeat, as soon as you put it in contact with the connector. THEN, the whole mass, including the coax, has to get heated up. If you have to hold the iron's tip on the connector for more than five seconds, something's wrong. An 80-100 watt iron with a heavy tip will do it in less than that, and do it well. The thermal mass of a tip that size ensures that, even though the tip temperature will drop, it will remain WELL above the solder's melting point, keeping the coax dielectric very cool, relatively speaking.

It's all about thermal mass.

 

[bob85]

imho beetle has it spot on,
the tentec video with the little needle tip lmao.

 

[mackmobile43]

I like using my 100 watt American Beauty model #3138.

 

[Beetle]

Mack - been using one just like yours for years (about 50 of them, to be exact!). I'm on my 4th tip. Or maybe the 5th - I may have lost count over the decades.

However, there's another type of iron - the kind used by stained-glass hobbyists. Weller Soldering Irons/Tips shows 80, 100 and 120 watt irons, and I can tell you that they work VERY well - even the 80 watt iron. That iron, with the supplied massive 3/8" tip, takes maybe a second longer than the American Beauty. MAYBE a second. Could be less; it isn't longer. Biggest benefit to these Weller irons is that they're a lot smaller physically, and lighter. Easier to use. I keep the American Beauty for jobs like making a dozen lengths of coax. For just one or two, I get the Weller hotted up.

I do not work for Weller nor have I been remunerated for this endorsement. I'm just one happy user.

 

[Captain Kilowatt]

Beetle,I'll second the Weller stained glass 80 watt iron. I use it sometimes and it works quite well. When I don't use it, I do use my OLD Weller D550 gun,not the new D550,and all it's 325 watts.Old Betsy as I call it is a real massive beast as far as guns go.

 

[BOOTY MONSTER]

Weller Soldering Iron, SP-120, Chisel Tip, $41.41
Weller Soldering Iron, SP-120, Chisel Tip, 120V: mro2go.com

Weller Soldering Iron, 175W, 12-1/2"L, 5/8" Chisel Tip $51.31
Weller Soldering Iron, 175W, 12-1/2"L, 5/8" Chisel Tip: mro2go.com

 

[357]

exactly what "changes" were you wanting to see?

Well I was hoping to see a flat match.
Supposedly with the choke, the coax lenth won't effect SWR.

I have 1.5-1 on CH1 and 1.1-1 on 28.305.
I adjusted the tuning rings DOWN almost to the bottom, this brought the 1.1-1 from 28.605 to 28.305, not nearly enough.
I figured my coax was radiating but it obviously is not.

Only thing I see is a 1db drop in recieve.

Guess I'll be climbing the tree again.:mellow:

 

[freecell]

"Well I was hoping to see a flat match."

then you still don't understand the purpose of the choke. it has nothing to do with VSWR and a high VSWR is no indication of feedline radiation.

"Only thing I see is a 1db drop in recieve.

that usually indicates that noise in the receiver due to common mode current on the outer shield of the feedline is being suppressed. that's one of the benefits of using a choke.