CAP Talk

Operations => Tools of the trade => Topic started by: wuzafuzz on January 09, 2009, 10:30:25 PM

Title: Disguise antennas for CAP
Post by: wuzafuzz on January 09, 2009, 10:30:25 PM
Some of you, like me, probably live in HOA's with antenna restrictions.  If anyone has experience using hidden or disguise antennas for CAP radios at their home, please share.  VHF and HF.

I've considered a Ventenna, but they don't seem to cover the necessary bandwidth. (I worked my way onto the HOA board  ;D but can't totally change the rules.)

Share your ideas and even photos of crafty installs!

Title: Re: Disguise antennas for CAP
Post by: Major Lord on January 09, 2009, 10:54:13 PM
I found an antenna that looks like two slinkies, and it worked pretty well in my attic for HF. Totally covert. I don't have room in my yard for a big-ticket tower, but I do have room for a vertical. I will probably attach U.S. Colors to the top. I have to confess my roof top VHF antenna is a Radio Shack ground plane hiding on the leeward side of my Chimney. I plan on buying and installing one of those MFJ verticals that covers HF to VHF and makes your house look like the soviet embassy.

Major Lord
Title: Re: Disguise antennas for CAP
Post by: MIKE on January 09, 2009, 11:20:12 PM
Dipole.  I'm thinking one you can string up in the attic or pull double duty as a clothesline.  Maybe run some plants up it.
Title: Re: Disguise antennas for CAP
Post by: Gunner C on January 09, 2009, 11:53:03 PM
Quote from: MIKE on January 09, 2009, 11:20:12 PM
Dipole.  I'm thinking one you can string up in the attic or pull double duty as a clothesline.  Maybe run some plants up it.

That would be interesting if someone puts wet wash on it during the local HF net!

[singing] You light up my wife [/singing]  :D
Title: Re: Disguise antennas for CAP
Post by: desertengineer1 on January 10, 2009, 12:14:59 AM
Eric,

Tomorrow I'll take a picture of mine and post it here.  I think you'll like. 
Title: Re: Disguise antennas for CAP
Post by: IceNine on January 10, 2009, 01:19:14 AM
Quote from: Major Lord on January 09, 2009, 10:54:13 PM
I found an antenna that looks like two slinkies, and it worked pretty well in my attic for HF. Totally covert. I don't have room in my yard for a big-ticket tower, but I do have room for a vertical. I will probably attach U.S. Colors to the top. I have to confess my roof top VHF antenna is a Radio Shack ground plane hiding on the leeward side of my Chimney. I plan on buying and installing one of those MFJ verticals that covers HF to VHF and makes your house look like the soviet embassy.

Major Lord

Pic or link?  I'd be interested in putting an antenna in my attic
Title: Re: Disguise antennas for CAP
Post by: Chief2009 on January 10, 2009, 01:32:05 AM
Talk to the ham radio guys in your area about this. They usually have some pretty ingenious ideas.

DN
Title: Re: Disguise antennas for CAP
Post by: Major Lord on January 10, 2009, 02:21:19 AM
Quote from: IceNine on January 10, 2009, 01:19:14 AM
Quote from: Major Lord on January 09, 2009, 10:54:13 PM
I found an antenna that looks like two slinkies, and it worked pretty well in my attic for HF. Totally covert. I don't have room in my yard for a big-ticket tower, but I do have room for a vertical. I will probably attach U.S. Colors to the top. I have to confess my roof top VHF antenna is a Radio Shack ground plane hiding on the leeward side of my Chimney. I plan on buying and installing one of those MFJ verticals that covers HF to VHF and makes your house look like the soviet embassy.

Major Lord

Pic or link?  I'd be interested in putting an antenna in my attic

I found one on E-Bay that looks about the same as mine, but seems a little improved. Mine was more bailing wire/bubble gummish....but it worked.

http://cgi.ebay.com/STEALTH-SLINKY-DIPOLE-HF-SWL-HAM-ANTENNA_W0QQitemZ320330068996QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item320330068996&_trksid=p3286.c0.m14&_trkparms=72%3A1234%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318%7C301%3A0%7C293%3A1%7C294%3A50

If the link is FUBARD, just go to E-Bay and type "HF antenna" good luck!

Major Lord

Title: Re: Disguise antennas for CAP
Post by: IceNine on January 10, 2009, 02:40:10 AM
Heh, I'm fairly certain that actually <IS> a slinky

Thanks for the link
Title: Re: Disguise antennas for CAP
Post by: Dirtman on January 10, 2009, 04:02:48 AM
start with this book

http://www.amazon.com/Low-Profile-Amateur-Radio-Publication/dp/0872594114

It has good info in it, you can set up a loop or folded dipole in you attic if you have room, or set up a loop on/around the eves of your house.  VHF is pretty simple as far as a J pole or ground plane in the attic.  Lots of guys around here run in attic antennas for use during storm season to avoid taking a direct hit from lightening vs their outside towers and long wires.

There was also a good article or two in one of the recent issues of QST about in attic antennas.  Give that a look also 

Getting ready to build our wing CV an in attic setup for VHF and HF.  He just moved into a "no outside antenna" covenant. 

Another idea is the HamStick dipole.  Do a web search, but it is two Hamstick whip antennas connected together to make what looks like a dipole.  I use these when camping and I don't have trees or room for a full sized dipole.  Buy the ones for 80mtrs with the adapter, get an antenna analyzer and trim them to the HF channel you wish, total length of the antenna for CAP HF work on mine is about 15 ft.  That will fit into about any attic.  Again a tuner will be needed in some cases. 

BTW you will need a tuner for a lot of the antennas you will find on the web and in that book.

Title: Re: Disguise antennas for CAP
Post by: JoeTomasone on January 10, 2009, 06:00:59 AM
I work the local VHF repeater with a j-pole in the window on the first floor.   

For HF, I have a dipole laying on the roof.  Not grand, but with a tuner it gets the job done.   

Title: Re: Disguise antennas for CAP
Post by: JAFO78 on January 10, 2009, 09:41:07 AM
Down here in FL, Disney has all their cell towers look like trees. EZ to tell cause the "tree" is higher then all the rest, but at lest they try. I wish I could post a photo, but don't have one, don't know how.
Title: Re: Disguise antennas for CAP
Post by: Dirtman on January 10, 2009, 02:25:51 PM
Like this Rob?
http://antennastructures.blogspot.com/2006/08/cellular-antenna-disguised-as-conifer.html (http://antennastructures.blogspot.com/2006/08/cellular-antenna-disguised-as-conifer.html)

Got picture of bird house as vhf but dont know how to post pictures yet.

Title: Re: Disguise antennas for CAP
Post by: JAFO78 on January 10, 2009, 09:20:06 PM
Yea that's like it but with Disney, you'd swear it was a tree. They are good at hiding things behind landscaping.
Title: Re: Disguise antennas for CAP
Post by: IceNine on January 10, 2009, 09:36:16 PM
I can't find much on radiation patterns maybe someone here will have some advice.

Peak of my roof runs North to South and is 40ft long.  The house is only 26 ft wide. 

I am almost geographically dead center in Illinois and a great deal of my HF work will be to the north of me.

Would I have much luck running the antenna along the peak, or possibly diagonally from corner to corner.

Or should I look at something completely different?  I see a lot of square and diamond loop designs but no
radiation patterns to help me decide.
Title: Re: Disguise antennas for CAP
Post by: addo1 on January 10, 2009, 09:54:50 PM
Quote from: Rob Goodman on January 10, 2009, 09:20:06 PM
Yea that's like it but with Disney, you'd swear it was a tree. They are good at hiding things behind landscaping.

  Yeah, I know what you mean.. When I was there awile back, we would go around trying to count how many we could find... :)
Title: Re: Disguise antennas for CAP
Post by: desertengineer1 on January 10, 2009, 11:53:15 PM
Can you see the antennas? 

Title: Re: Disguise antennas for CAP
Post by: desertengineer1 on January 10, 2009, 11:55:09 PM
Here's what's really there.  You have to look really close to see the outside HF.

Red = main radiator.  Green = Ground plane / radial.  Blue = Ground Rod. 

The distances are rough.  The tuner is fed with Andrew LDF4-50 Heliax.  Altogether, HF gets really good coverage in ALE and SSB.

Title: Re: Disguise antennas for CAP
Post by: IceNine on January 10, 2009, 11:56:52 PM
Low light, NO FAIR!!

Nicely done by the way
Title: Re: Disguise antennas for CAP
Post by: desertengineer1 on January 11, 2009, 12:00:35 AM
Quote from: IceNine on January 10, 2009, 11:56:52 PM
Low light, NO FAIR!!

Nicely done by the way

Unfortunately, I work 7 days a week and don't see home in any other light  :)

The VHF is obviously in the attic, perched under the peak of the roof frame.

I get EXCELLENT coverage of the Southeast Region nets.

For you comm folks, this is the "Oil Well" station.

Cheers,

James
Title: Re: Disguise antennas for CAP
Post by: wuzafuzz on January 11, 2009, 12:50:31 AM
Excellent example of low visibility antennas.  Thanks for sharing.
Title: Re: Disguise antennas for CAP
Post by: Dirtman on January 11, 2009, 02:25:14 AM
Well Done! 

What type and gauge wire?  Flexweave?

Anyone ever noticed or said anything? 

Title: Re: Disguise antennas for CAP
Post by: desertengineer1 on January 11, 2009, 03:03:26 AM
Quote from: Dirtman on January 11, 2009, 02:25:14 AM
Well Done! 
What type and gauge wire?  Flexweave?
Anyone ever noticed or said anything? 

Thanks,

Strangely, I'm using 18 Ga galvanized steel wire (It works well!).  Third generation so far. 

Magnet wire broke every week or so went to 22 ga steel.  Was getting a little tired of the "Why are you casting a fishing line at your tree?" questions.  (Funny, people around here are nice, but easily confused). 

22 Ga Steel wire lasted a little over a month before several 75 mph thunderstorms brought it down.  Upgraded to 18 Ga and has held very well for the past two months.

The next upgrade will be the flexweave - when I can find the time.

Title: Re: Disguise antennas for CAP
Post by: ♠SARKID♠ on January 11, 2009, 03:32:50 AM
Quote from: desertengineer1 on January 11, 2009, 12:00:35 AM
Quote from: IceNine on January 10, 2009, 11:56:52 PM
Low light, NO FAIR!!

Nicely done by the way

Unfortunately, I work 7 days a week and don't see home in any other light  :)

The VHF is obviously in the attic, perched under the peak of the roof frame.

I get EXCELLENT coverage of the Southeast Region nets.

For you comm folks, this is the "Oil Well" station.

Cheers,

James


So that's you!  You gave me a relay a while back into Mississippi's net.  Small world, thanks!

- Bluemound 317
Title: Re: Disguise antennas for CAP
Post by: cap235629 on January 11, 2009, 07:36:54 PM
QuoteI found one on E-Bay that looks about the same as mine, but seems a little improved. Mine was more bailing wire/bubble gummish....but it worked.

http://cgi.ebay.com/STEALTH-SLINKY-DIPOLE-HF-SWL-HAM-ANTENNA_W0QQitemZ320330068996QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item320330068996&_trksid=p3286.c0.m14&_trkparms=72%3A1234%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318%7C301%3A0%7C293%3A1%7C294%3A50

If the link is FUBARD, just go to E-Bay and type "HF antenna" good luck!

Major Lord

Does this antenna with a tuner work across the CAP HF spectrum meaning will it work well on AA as well as AI?

If so, this may be the solution for my attic, if it works well in the attic that is.....
Title: Re: Disguise antennas for CAP
Post by: Major Lord on January 12, 2009, 12:56:38 AM
Theoretically, the way you tune these is to stretch them to your desired frequency of operation less some magic number, or just stretch it out for best match.  I stretched mine out as far as I had room for and used my Icom autotuner to do the dirty work of tuning it up. I think a manual tuner would be optimal, especially since I wanted to have good performance on our 75/80 Meter range. I may try to set this antenna up in our converted-dormitory Squadron building on Travis. It looks like a mast is a no-go there.

Major Lord
Title: Re: Disguise antennas for CAP
Post by: Dirtman on January 12, 2009, 05:02:19 PM
Ice

I cant find the ARRL pub I was looking for this morning on radation patterns but try these to see if they help you

http://www.kyes.com/antenna/navy/rpatterns/radiapat.htm (http://www.kyes.com/antenna/navy/rpatterns/radiapat.htm)

http://www.aerocomm.com/docs/Antenna_Tutorial.pdf (http://www.aerocomm.com/docs/Antenna_Tutorial.pdf)

http://en.wikipedia.org/wiki/Dipole_antenna (http://en.wikipedia.org/wiki/Dipole_antenna)
Title: Re: Disguise antennas for CAP
Post by: blackrain on January 15, 2009, 06:05:28 PM
I have a question for you amateur radio types. I own a Yaseu VXA-220 aviation handheld. Do any of you know of a flexible antenna like those sold by Diamond or Comet which are used on amateur hand-helds that are resonant on the 118-137 aviation band that could be used on my handheld? I'm trying to make it easier to fit in my flightsuit pocket. Thanks
Title: Re: Disguise antennas for CAP
Post by: JoeTomasone on January 15, 2009, 06:46:59 PM
Quote from: blackrain on January 15, 2009, 06:05:28 PM
I have a question for you amateur radio types. I own a Yaseu VXA-220 aviation handheld. Do any of you know of a flexible antenna like those sold by Diamond or Comet which are used on amateur hand-helds that are resonant on the 118-137 aviation band that could be used on my handheld? I'm trying to make it easier to fit in my flightsuit pocket. Thanks

I would think that one of the 2m mini-flexie-duckies by Comet and the like would be fine (SWR-wise) for infrequent use.   Maybe I'll put mine on the antenna analyzer and see how it fares.   Likely won't get to it for another 10 days at minimum since I will be out of the country next week.
Title: Re: Disguise antennas for CAP
Post by: wuzafuzz on January 17, 2009, 01:29:45 PM
Does anyone know if CAP Micom 2 radios have an antenna tuner built in?  I did a few searches on the web to some Micoms including an internal tuner, but haven't found a conclusive answer.
Title: Re: Disguise antennas for CAP
Post by: RedFox24 on January 17, 2009, 03:35:26 PM
No, they don't.   Or at least the ones I have used and had issued to me.  There is or should be a bar graph that shows reflected power when you key up and talk.  The lack of a tuner is why it seems CAP is so hung up on the B and W folded Dipole.  Better results are obtained with a simple dipole and an antenna tuner.
Title: Re: Disguise antennas for CAP
Post by: desertengineer1 on January 17, 2009, 06:55:27 PM
Speaking of that...  I had to strike the MICOM 3 station this morning.  The remote tuner took on a small amount of water - even after I had sealed it liberally with Silicone.  Galvanic corrosion eventually shorted the regulator and killed the tuner.  After cleaning all the corrosion and drying it under a fan for a day, it is still dead.

Soo...  Be careful with the remote tuners around moisture.  Hope I can get another so the station can go back up.
Title: Re: Disguise antennas for CAP
Post by: ♠SARKID♠ on January 18, 2009, 01:12:36 AM
Spill your drink?   ;)
Title: Re: Disguise antennas for CAP
Post by: wuzafuzz on January 18, 2009, 01:24:09 PM
Quote from: RedFox24 on January 17, 2009, 03:35:26 PM
No, they don't.   Or at least the ones I have used and had issued to me.  There is or should be a bar graph that shows reflected power when you key up and talk.  The lack of a tuner is why it seems CAP is so hung up on the B and W folded Dipole.  Better results are obtained with a simple dipole and an antenna tuner.
Thanks, that's helpful to know.
Title: Re: Disguise antennas for CAP
Post by: RedFox24 on January 18, 2009, 05:25:58 PM
Desertengnieer1

Oil well antenna?   Looks like a classic inverted L to me.......?  Where from or what is an Oil Well antenna.  Never heard of that one before.  BTW nice setup making what you got to work with work!

On a side note, don't know where your located, but here in southern Illinois (not central but deep Southern!) with the extreme fluctuation in air temps, even in a 12 hr period, sealed containers build up moisture.  It has gone from -1 to +45 in a 24 hr period over the last two days.  I have found that you need to put some of those silicate packs into sealed boxes outside and inspect them regularly.  For me, a good indication is when my garage floor, tool boxes and work bench start beading up moisture.  Not the same as moisture leaking in from rain, but just as damaging. 
Title: Re: Disguise antennas for CAP
Post by: IceNine on January 18, 2009, 06:05:22 PM
Quote from: desertengineer1 on January 11, 2009, 12:00:35 AMFor you comm folks, this is the "Oil Well" station.

Read that again.

Oil Well is Oklahoma's Call sign
Title: Re: Disguise antennas for CAP
Post by: RedFox24 on January 18, 2009, 07:29:55 PM
Duhh......Sorry, just a little slow this Sunday Afternoon...............
Title: Re: Disguise antennas for CAP
Post by: desertengineer1 on January 18, 2009, 10:12:40 PM
Quote from: RedFox24 on January 18, 2009, 05:25:58 PM
Desertengnieer1

Oil well antenna?   Looks like a classic inverted L to me.......?  Where from or what is an Oil Well antenna.  Never heard of that one before.  BTW nice setup making what you got to work with work!

On a side note, don't know where your located, but here in southern Illinois (not central but deep Southern!) with the extreme fluctuation in air temps, even in a 12 hr period, sealed containers build up moisture.  It has gone from -1 to +45 in a 24 hr period over the last two days.  I have found that you need to put some of those silicate packs into sealed boxes outside and inspect them regularly.  For me, a good indication is when my garage floor, tool boxes and work bench start beading up moisture.  Not the same as moisture leaking in from rain, but just as damaging. 

LOL.  Lack of sleep will do that :)

Originally, the factory seal was pretty much useless.  If I know we're going to have T-storms, I'll disconnect the coax cable completely and tie the antenna wire to ground in case lightining hits.  I don't want it going into the house (was before I installed a line of ground rods).  A day after a rain I went out to reconnect the coax.  When I picked up the tuner, water just poured out of a corner.  It had flooded completely.  Fortunately, after drying for a day and reseal, it worked fine.  I installed a tube of dessicant in some of the free space.  I removed the coax bulkhead, ground bolt, and antenna bolts, filled them with silicone and tightened.  I even put a liberal seal of silicone over the edges after it was tightened down.  I thought it was a pretty serious water resistant job!

It worked great for about three months.  Ran ALE 24/7 - except evenings I was on the SER nets.

But the other night I tried to check in SSB and no one responded.  Then I noticed the TX bar wasn't indicating anything.  I commanded manual sounding on the ALE net and saw all channels had maximum SWR indication.   When I pulled the tuner open, I saw a small amount of water had seeped in and corroded the solder joints around the +5 V regulator.

Spent an evening cleaning it up (hoping the corrosion was just causing the regulator to reset) dried it for a couple of days and tried it again.  No change.  It's dead.

So now, I'm not sure what to do.  Left a message with the wing DC.  I'm hoping CAP has warranties with MOBAT.  If not, a new tuner will be expensive.

I'll put the next tuner inside a fully sealed enclosure.  Even have a couple of pounds of activator dessicant in the garage.  This will not happen again.

Hopefully we can get the word out to everyone else using RDP's NOT to let the tuner get wet.

:(