Scale Antenna

[mylo]

All,

I would like to run my receiver antenna in the same place where the bow antenna is on the actual type VIIc/41, if that would in anyway benefit me. Given the size of my boat, I feel an actual receiver antenna run from the conning tower to the bow would be to scale in appearance.

Could I expect better underwater signal reception since the antenna would be so exposed and unobstructed, or is there no advantage to running the antenna like that ? Has anyone ever tried ?

Thanks,

Mylo

[skip asay]

Mylo -

Actually, there would be

Mylo -

Actually, there would be no noticeable benefit except perhaps in a swimming pool with its less than desirable water. I've seen boats exceed 30' of depth with the antenna inside the hull (in fresh water) so I'll say that you would be wasting your time. Also, you would have to have some sort of waterproof connection in the antenna wire to allow you to remove the deck. It's not worth the aggravation. Just make sure that the wire is stretched out along the hull and doesn't double back on itself. (That's not a likely situation with the size of your boat!)

Skip Asay

[mylo]

Skip,

I appreciate that. For

Skip,

I appreciate that. For sure, running the antenna outside the boat was going to be a pain, but I thought if it would allow for deeper signal, I would do it.

.....HOWEVER

If a guy can get 30' in fresh water by running the antenna inside a dry WTC, that's more than enough. Serious pucker factor if she got down that deep.

It seems to me that the antenna has to be a certain length for any given frequency, not shorter, not longer. Is it best to run it as straight as possible ? Inside the WTC ? Outside ? I'm assuming you want to keep it away from the motors ?

Many thanks,

Mylo

[skip asay]

"Is it best to run

"Is it best to run it as straight as possible ?"

Yes.

"Inside the WTC ? Outside ?"

As long as you seal the end of the wire, outside is good.


"I'm assuming you want to keep it away from the motors ?"

True enough. Run it forward.

Skip Asay

[theo]

Antenna length

As for the antenna length, trying to figure out what a fractional wave length should be for a given frequency is an object in futility. Don't bother, rather, maintain the length of antenna that came with the receiver as it most likely has been tuned, during the factory alignment process for maximum field strength. The main reason for leaving it at it's original length is because the "final" (Transmitter RF power circuit) in the transmitter has RC networks that allow for antenna lengths shorter then normal for a given frequency. The other option, assuming you have experience in designing RF circuits, is to redesign the transmitter final so that you can use a longer antenna. Needless to say, a waste of time from a practical point of view.

Jack, the new kid on the block

[mylo]

Jack,

You might as well

Jack,

You might as well have been talking Chinese.

Skip,

Thanks for the feedback. Run 'er straight....run 'er up front.

Mylo

[theo]

OOOOOP!!!!

Mylo,

OOOPS!!!
In my comments, I wrote "Transmitter" and what I meant was Receiver Antenna and Receiver RC circuits. In any event, when you buy/bought the R/C receiver, it was factory tuned for the specific antenna length that the receiver came with. Some days, I just seem to have more senior moments then others!!!

Jack

[mylo]

See........I didn't even know that

See........I didn't even know that you screwed up what you were saying.

I'm more of a.....foam shaper / sander /epoxy / CA glue kind of guy as opposed to an electronics expert, which is why I'm struggling so damn much at trying to figure this WTC stuff out.

Mylo

[mike dory]

Mylo - Your U-boat, does

Mylo - Your U-boat, does it have a "commander ant. pole", Should be on the side of the conning tower running up as high as the scopes If you do, think about making it be the real ant. Most of the late war boats had this ant. In my experence, when you find your self running in less then perfect water and trust me there is alot of that around, You could connect your radio ant. to a 1/16 inch X 6 inch long, plastic covered wire (Plastruct makes them, You'll find, at your hobby shop.) and run it through a short brass tube making it "the commander ant. pole" This would allow you to run, even in salt water. At periscope depth. Not that you would want too. I've run in Salt water for years, all you need to do is keep about an inch of ant. out of the water to do it. It will give the very best reception no matter what water you find your self running in. Doing this makes it easy to put up or disconnect. I'll show you mine at the regatta, works well and has stood the test of time. See ya then and Best Wishes... Mike Dory

[mylo]

Mike,

I like the idea.

Mike,

I like the idea. Would the "commander ant. pole" increase submerged depth reception ? Not that I want to run it that deep, but it would be nice if I could maintain signal in the event she went deep "accidentally".

Mylo

[cstranc]

Mike,
I thought that changing

Mike,
I thought that changing the length of your antenna wire was a bad thing?

Or are we looking at "adding 6" to the antenna will degrade it's performance 20%, but when you are underwater and only the last 1" of the antenna is getting a signal it's worth it".

[tsenecal]

Chris,

If your scale antenna is

Chris,

If your scale antenna is 6" long, cut 6" off the original antenna, keeping the overall length the same.

[cstranc]

That sounds simple enough.

I have

That sounds simple enough.

I have heard people say you need to seal the antenna wire end or else water will travel down the inside of the antenna and directly into the reciever. Is this a concern if you are leaving a stretch of bare wire to connect to the 6" extension?