Skipjack 1/72

[alad61]

Ignore my last post... Obviously my phone suffers lag...BLUSHERVery Angry

[alad61]

Good Point....except I havent seen anything on your suggestions. Could you post a picture?

Mark if you go to the knowledge base for the skipjack instructions I'm pretty sure David shows som pics of the layout in the last pages...

[greenman407]

Dave....you are the Man, but heres my thinking on Receiver placement. Ive been using D&E WTCs for about 8 years now. On all of them including the Subdrivers, the antenna wire lies alongside and the Antenna post is almost touching the electric motor. Since the most likely path into the receiver is thru the antenna wire, and I have had no ill results ,I wouldnt think that there would be a problem. Also this is a Sombra with superior stray signal rejection.

I will now slink away into the corner with my Dunce cap on.:biggrin:

[greenman407]

Thanks Alec, Ill check that.

[He Who Shall Not Be Named]

Dave....you are the Man, but heres my thinking on Receiver placement. Ive been using D&E WTCs for about 8 years now. On all of them including the Subdrivers, the antenna wire lies alongside and the Antenna post is almost touching the electric motor. Since the most likely path into the receiver is thru the antenna wire, and I have had no ill results ,I wouldnt think that there would be a problem. Also this is a Sombra with superior stray signal rejection.

I will now slink away into the corner with my Dunce cap on.:biggrin:

Your point is well taken, Mark. And that antenna is indeed in the worst possible location -- but design drove me to put it there.

But, why tempt fate and let RF into the receiver board when you don't have too?! Distance (the inverse, square law) works for us if we use it.

M

[He Who Shall Not Be Named]

Dave....you are the Man, but heres my thinking on Receiver placement. Ive been using D&E WTCs for about 8 years now. On all of them including the Subdrivers, the antenna wire lies alongside and the Antenna post is almost touching the electric motor. Since the most likely path into the receiver is thru the antenna wire, and I have had no ill results ,I wouldnt think that there would be a problem. Also this is a Sombra with superior stray signal rejection.

I will now slink away into the corner with my Dunce cap on.:biggrin:

Your point is well taken, Mark. And that antenna is indeed in the worst possible location -- but design drove me to put it there.

But, why tempt fate and let RF into the receiver board when you don't have too?! Distance (the inverse, square law) works for us if we use it.

M

[greenman407]

Very well sir, Thy will be done. Ive scoped out a spot upfront for it.

[greenman407]

The preferred method of smoothing and sealing your silicone, spit on your finger and carefully wipe around your victim. If you dont like the spit idea ,you can use Petroleum Naphtha, Paint thinner/mineral spirits, xylene, or lacquer thinner to coat your finger. Just dont press too hard or youll remove all your silicone.

[greenman407]

New location for the Sombra. The BEC will go right underneath it under the shelf, above the pump.

[alad61]

Your point is well taken, Mark. And that antenna is indeed in the worst possible location -- but design drove me to put it there.

But, why tempt fate and let RF into the receiver board when you don't have too?! Distance (the inverse, square law) works for us if we use it.

M

i put a couple of heat shrink lengths over the aerial wire where it sits near the motor then I slipped a length of styrene tube over that to help shield the wire from interference re the motor. To me it seemed to cut back on the glitching and occasional jitters coming out of the rx.

[alad61]

New location for the Sombra. The BEC will go right underneath it under the shelf, above the pump.
[ATTACH=CONFIG]23937[/ATTACH]

Mark i put the rx on its side up against the vertical section, the adf on the horizontal and bec under the shelf as you suggest for your bec

[trout]

If you are shielding the rf interference are you not also shielding the regular signal too? If that is true does that mess up the ideal antenna length for the wavelength being used?
Curious minds want to know more......

[alad61]

Tom I'm only shielding the antenna wire that runs near the motor not the entire length.

[roedj]

If you are shielding the rf interference are you not also shielding the regular signal too? If that is true does that mess up the ideal antenna length for the wavelength being used?
Curious minds want to know more......

I have experience designing antennas for amateur radio usage.

Basically, the antenna length as supplied is dependent on the antenna being straight and in free air (no surrounding metal close by) if it is a resonant frequency design.

Any variation from those two conditions will change the resonant frequency of the antenna. This assumes that the antenna is of a resonant frequency design. If it's not, if it's an 'active' antenna, then length still matters just not so much. I have been trying for years to get a manufacturer to state which type of antenna they use - so far without luck.

If it is a resonant design then twisting it up in a ball or loop, shielding a part of it or any other variation from the conditions listed above will completely change the resonant frequency.

If it were my concern - I wouldn't be overly concerned. I've seen antennas that look like a rat's nest still work.

Dan

[trout]

Thank you Dan, that was helpful! Very helpful.
David likes to say "it is not rocket science" and I am learning how in so many ways that is true, but antenna dynamics seems to go beyond rocket science it goes into the realm of magic and pixie dust to me.
Alec, I hope my question did not come across as questioning you or your abilitities. It is not. I respect your skills and knowledge immensely. It is me just trying to sort out the little knowledge I have.