Antennas

[secrtwpn1]

What do you guys do with your antennas? Inside the cylinder or outside? Also, if you have photos.....

Thx
Farlan

[Ralph --- SSBN 598]

All my antennas are inside the cylinder.

Skipjack the antenna goes along the side of the piston back to front and returns.
antenna is the yellow wire.


Akula II is the same other than it is a dry hull.
The antenna is in the clear/white U bent tube along the side from the rear compartment to the front and back.


George Washngton antenna is wrapped on a flat piece of 1/16" sheet plastic sort of a coil so the antenna wire does not cross itself. Itis all in the rear compartment.
The antenna is in the rear compartment wrapped around the plsatic sheet.
Sorry the photo does show it.
This boat is only 3" in diameter and the rear cylinder is 1.5" in diameter.


The Gato will have the antenna in the rear compartment simular to the GW.
This is the antenna on the plastic sheep piece.
This was how it was during the first water trials.
The cylinder is currently disassembled for ballast system change from water pump to air pumps.


For antennas that come out of the cylinder, Mike or Will can help with that.
Mike when he first started bilding/running submarines it was in salt water and his boats reqired the antenna to be above the water surface to work at all.

[bob the builder]

I typically run them outside. This allows for full-length extension and maximum separation from any noisy electronics inside the cylinder. If you put it in a small diameter rubber tube, this also gives you a method to test the cylinder for leaks. You unplug the end, submerge your cylinder and blow into the tube. You can easily spot any leaks that are there, and precisely where they are.

[Ralph --- SSBN 598]

Bob,
My builds all have a Schreader Valve on the front end cap.
I have a hose with the threaded fitting on it to do exactly what you are doing.
The Schreader has no inside parts.
I also make a brass rod hook that I can reach through the Schreader to reach the on/off switch.

The Schreader most importantly lets me take the valve cap off for transportation up and down the 5000' I have to travel to the lake.
Forgot once and the end cap popped off and scared me while driving up the hill.
----------------------
Farlan,
Inside or Outside depends on how you want it to be.
Both ways work.
Inside requires a little placement design to limit the electrical noise of the motors. (brushed)
Outside requires another fitting through an end cap. (outside allows you to run in electrically dirty water (brackish or salt) as long as the antenna is 1/2" or more above the surface)

[secrtwpn1]

So I glued together 3 pieces of dowel and wrapped the antenna around it........Could not attach the picture......

[secrtwpn1]

Figured it out...................

[salmon]

Farland,
I am not sure how it applies to our frequency, but in networking, wood (including books) can absorb or severely impact radio signals. Now to qualify that, it is in GHz range and not our MHz range. So, my point is I do not know how well the dowels ill or will not impact the frequency. However, in your testing, if range is poor, keep this as something to consider.
Maybe on of our electronic experts can tell me I am full of stuff or corroborate what I am saying.
Peace,
Tom

[secrtwpn1]

Ok. I'll be standing by for more info......

[crueby]

If there are materials that do effect our mhz ranges, that would be good to know.

[Ralph --- SSBN 598]

Just a though on my part.

The wood dowels take up a lot of room in the cylinder.
I see three in your photo.

I also would consider the absorbtion of the sign by the wood.

My thought is this, I would try using 2 plastic ball point pen barrels.
They are easy to come by and sheap if you have to buy new.

The plastic pen barrels are lighter in weight than wood dowels.

Farlan, how much room do you have for the antanne piece.
Length and width?

I can send you a piece of sheet plastic to see if it will work for you.
It is 1/16" thick and you cut it with a razor knife or scissors.

If you want it, send me a mailling address by e-mail.
I'll be in town and can mail it Monday.

Ralph

[secrtwpn1]

Thanks, but I'm sure I can dig up some old pens around the house....

[secrtwpn1]

Same set up, but this time with clear acrylic rod I found in my workbench..................