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Author Topic: Help me find the ultimate portable/stealth wideband antenna  (Read 3736 times)

Offline radiozed

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Maybe an impossible quest, but I thought if anybody would know it would be some of the experts here.  Early next year I'll be embarking on an expedition where I'll be spending a couple of weeks on one of the highest mountains in the world.  I thought it might be a good opportunity to try some high altitude broadcasting with nary an obstruction anywhere in sight.   ;)  I haven't decided on what radio to take yet (right now thinking of taking one of Stretchy's Lulu transmitters, but may also take along my Yaesu FT-817 so I have some wider frequency/mode options).  In whatever setup I use, I wouldn't plan on broadcasting at more than 40 watts.  So here are my limitations:

- has to be lightweight and fit in to my backpack

- dipoles are out of the question.  being on a mountain like where I'll be, there would be nothing to attach it to.

- has to be fairly stealthy.  Yes, I'll be on a remote high altitude mountain, but so will a lot of other climbers.  Since there isn't much in the way of 21st century technology to keep climbers entertained (except maybe their ipod), people still tend to pass the time by listening to AM/FM/SW radio.  The last thing I want is to have one of the 300 or so climbers in basecamp (not to mention the dozen or so park service rangers) coming across my signal and then simultaneously noticing the one North Face tent with the 8' vertical propped up outside of it.   ;D  For this reason, something like a hamstick dipole probably isn't the best idea either. 

With these limitations in mind, about the only thing I've found so far is this:

http://www.eham.net/data/classifieds/images/263735.jpg  (the MFJ-1899T)

Seems like it would fit the bill.  I could broadcast from inside the tent and run the antenna up through the vestibule zipper and nobody would probably be the wiser, especially after dark.  Yes, I know from reviews that they're not known to be especially efficient, but I'll be up over 7000 meters so I think my signal should still get out fairly decent.  The one problem I see is that it'll only handle 25 watts max.  Maybe if people don't think I'll need anymore than that I'll stop obsessing and just take it along.  The other limitation I see is that this little guy (as well as the similar "Miracle Whip" antenna) are typically said to require some random length of counterpoise to have any hope of getting a decent signal out.  If it's unavoidable, it's unavoidable and I'll just have to deal with it.  I just have this fear of stringing out 18' of thin copper wire and either having someone trip over it (crampons will trip you up on just about anything if you're not careful) or having someone notice it and say, "hey, what's this?" and pick it up and risk getting an RF burn. 

One last alternative I've thought of would involve building my own.  Take two 2' lengths of fiberglass pole with a threaded connection in the middle.  Hand wind it with copper wire and cover said wire with black tape.  Unscrews in the middle for easy packing.  Get in to camp and screw the two ends together and I have a 4' vertical.  Put a fake handle on the top and a snow basket on the end and it looks no different than the hundreds of ski poles that other climbers have propped up outside their tents.  Downside is I'd certainly need to take a tuner along and it would probably still require a counterpoise of some sort.  Not perfect, but maybe doable.  Could probably handle far more than 25 watts too. 

Any other ideas from group?

Offline Stretchyman

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Re: Help me find the ultimate portable/stealth wideband antenna
« Reply #1 on: August 17, 2016, 1556 UTC »
Hi Zed as per my PM and good to mention here........

A vertical using a telescopic fiberglass pole, full 1/4 Wave and raised radials.

Simple, Lightweight and Efficient!

Hope you use one of my TX's to do the business!

 ;)


'It's better to give than receive' so why RX when you can TX!

                            Buy one from me, NOW!

Great discounts on ALL my transmitters if purchased via HFUnderground


                                              ;)

Offline radiozed

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Re: Help me find the ultimate portable/stealth wideband antenna
« Reply #2 on: August 17, 2016, 1633 UTC »
Perhaps I'm misunderstanding something, but wouldn't a full 1/4 wavelength antenna for 43 meters be over 30' long?  That's a mighty big ski pole!   ;)

Offline radiozed

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Re: Help me find the ultimate portable/stealth wideband antenna
« Reply #3 on: August 18, 2016, 0327 UTC »
Yikes!  Nearly 300 views and no further answers.  I take it I'm on a fruitless search for the "perfect" antenna.  I've spent the day researching the options some more and it seems there's probably not many better options than what I bought, which is the MFJ-1899T.  Others point to the "Miracle Whip," saying that the MW is better if I don't want to use a counterpoise and the 1899 is better if I'm willing to do so.  Answer has been self solved, although I may still go and get myself a lightweight QRP antenna tuner to round out the package. 

Offline loul

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Re: Help me find the ultimate portable/stealth wideband antenna
« Reply #4 on: August 18, 2016, 0952 UTC »
Here in New Zealand multi-day hikers can hire a "mountain radio" for safety purposes - and to get the weather forecasts - which transmits and receives on SSB at around 3.261kHz. It's supplied with a thin plastic-coated wire dipole cut for this frequency, with light speaker cable as the lead. Hikers generally try to get the middle up on a tree branch, or a dead stick. In other words, it's jolly close to the ground. However, two options spring to mind (and I won't object if you think them fanciful, impractical, or just too unstealthy) - (1) the thinnest  5 or 6m of a 12m Spiderbeam pole (it comes with 12X1m telescopic sections); and enough cord for two guylines perpendicular to the wire direction; or (2) wrecking a 12m Spiderbeam by cutting down the sections to, say, 650mm, and having more sections (with guylines as before). I attach the dipole 800mm or so below the top, as the top of the thinnest section is too slender to support 46m of wire. I took the full 12m Spiderbeam hiking once and wouldn't do it again!! A 1m long, thick, heavy pole in the pack isn't much fun! This setup would possibly give you as much effectiveness as what is used in the mountains here. I use electrical insulation tape to stop the sections untelescoping, but in cold temperatures it tends to be harder to get off; there may be a better tape to use. Regards.
P.S. I've put one set of cutouts into the dipole and intend to install another set, to match it to other particular frequencies of interests - just banana plugs, and short cord sections to connect the bits of dipole together at the cutouts and at the top.
« Last Edit: August 18, 2016, 0958 UTC by loul »

Offline radiozed

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Re: Help me find the ultimate portable/stealth wideband antenna
« Reply #5 on: August 18, 2016, 1359 UTC »
No, I very much appreciate it.  What I wouldn't give to have a tree up there somewhere.  But it's essentially like the surface of the moon.  A few boulders that might be 4 or 5 feet high, but otherwise a barren wasteland of gravel, snow, and ice.  In basecamp there is a 20' steel tower that the park rangers and outfitters have some of their antennas mounted to for emergency communications, but that's it.  If I was feeling really brave I could always try to string a wire up there, but there'd be no way to do it without being seen.   ;D  Plus, it wouldn't do me any good during my time in all the other camps.  I think for right now my plan is to stay with the MFJ.  Ultimate portability, and despite having poor efficiency, I'm still hedging my bets that being on the highest rock in the hemisphere will get my signal out pretty well.  Or maybe just down in to the nearest village.   :D

Offline Fred Smith

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Re: Help me find the ultimate portable/stealth wideband antenna
« Reply #6 on: August 18, 2016, 1607 UTC »
Just try a higher frequency.

 If you transmit on the traditional pirate band on 43 meters I doubt anyone will hear much of it anyway. Inefficient antenna, low power, along way to an audience. If you just want to be heard near the summit just use an FM transmitter, range could be quite good, line of sight etc.. If you really want to do HF try something in the 19 meter band, 15070 khz is a European frequency 1/4 wave would be 15 1/2 ft. Or this, http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=11616

And if your in the right part of the world and get caught we will never hear from you again (spy) so have fun
FT-920, SDR Play and others. 80 meter doublet/openwire feed, 80/10 OCFD, 400 BOG  NE/SW unterminated

Offline moof

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Re: Help me find the ultimate portable/stealth wideband antenna
« Reply #7 on: August 19, 2016, 0124 UTC »
Small package and portable and can do the damage down to 6900 I can vouch for the buddipole deluxe package. It is on the expensive side at 175. Just leave clips off and it goes below 40m. It is super touchy about counterpoise length. It can go 2.5 to 1 down to 1.3 to 1 simply laying down the 6 inch kite winder one more width either way. It is about half the volume of the smallest laptop briefcase shaped bag.

Offline Fred Smith

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Re: Help me find the ultimate portable/stealth wideband antenna
« Reply #8 on: August 19, 2016, 0203 UTC »
He's going to be in the Himalayan mountains. How much a 43 meter audience will he have?
FT-920, SDR Play and others. 80 meter doublet/openwire feed, 80/10 OCFD, 400 BOG  NE/SW unterminated

Offline MDK2

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Re: Help me find the ultimate portable/stealth wideband antenna
« Reply #9 on: August 19, 2016, 0336 UTC »
You should come to Colorado before Labor Day and try that from the top of either Pike's Peak or Mount Evans, both 14ers where you can drive to the summit.
Denver, CO.
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Offline radiozed

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Re: Help me find the ultimate portable/stealth wideband antenna
« Reply #10 on: August 19, 2016, 1351 UTC »
I've heard those buddipole systems are the way to go, but the problem for my purposes of course are that they're noticeable as a tx antenna to most people.  A few feet of a shiny telescoping antenna sticking out of the top of a guy's tent though?  Most likely just some guy listening to his AM/FM/SW radio.   ;)  A good point was made earlier that I hadn't really thought about...getting pinched probably wouldn't be the same as at home.  At home some guy shows up at the door and wags his finger and warns me not to do it again.  There?  Maybe a bunch of paratroopers descending on basecamp in a chopper to drag me off stuffed in a duffle bag.  Incognito definitely sounds like the way to go.   ;D 

Offline radiogaga

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Re: Help me find the ultimate portable/stealth wideband antenna
« Reply #11 on: August 19, 2016, 1630 UTC »
I would be a little concerned carrying a txmitter into a foreign country...
Unless you have big cajones...

rgg

Offline radiozed

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Re: Help me find the ultimate portable/stealth wideband antenna
« Reply #12 on: August 19, 2016, 1711 UTC »
I would be a little concerned carrying a txmitter into a foreign country...
Unless you have big cajones...

rgg

Well, all expeditions carry a transmitter of some sort, plus sat phones.  Last time I was there I was packing an Iridium as well as a field programmable VHF.  Everyone else is packing them around as well.  But an amateur radio transmitter is admittedly a different deal.  I'll go read up on import restrictions to see what they might have on that sort of equipment. 

Offline radiozed

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Re: Help me find the ultimate portable/stealth wideband antenna
« Reply #13 on: August 20, 2016, 1246 UTC »
Poured through all the import restrictions and there is nothing whatsoever about bringing radio transmitters in to the country (perhaps the reason why I've never been hassled about it in the past). Funny thing is that they DO have restrictions on bringing in cellular telephones that are over a certain value.  I guess all of us that were there last time packing around iPhones probably just put on the customs form that it was worth $10.00.    ;D

Offline Josh

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Re: Help me find the ultimate portable/stealth wideband antenna
« Reply #14 on: August 20, 2016, 2156 UTC »
I'd be tempted to try a dipole fed with rg177 or rg58, using some pole to support the feed off the ground, and the ends held down by rocks or yeti or what have you.
Conveniently located near Vincennes Indiana.