Military UHF SATCOM Antenna Question

[qc]

Hi, I would like to find out if anyone has tried Myers Engineering International UHF Satcom Antenna's. http://www.myerseng.com/UHF_satcom_antenna.html. Are they any Good?


Thanks

 

[K2GOG]

did you find a great deal on ebay or are you thinking to buy direct from them?

 

[prcguy]

I have not heard of these in the US inventory or seen any surplus yet. Anything like this new will be very expensive.
prcguy

 

[qc]

Hi, Yes I was thinking to buying direct from them. I also found a company called Timestep http://www.time-step.com/products_inmarsat.htm they have a 260MHz Yagi Antenna for $99. they also sell a Preamplifier for $99 but they said that the Preamplifier needs a 12v power supply. I plan on using my BC250D Scanner I also plan on buying a BCD996T but I don't know if they supply the 12V for the Preamplfer. I'm new to UHF Satcom.

Thanks

 

[prcguy]

A new satcom antenna from Meyers is going to be a lot of money, most small fold up satcom antennas exceed $2k new. There are lots of good deals around on Dorne & Margolin and Trivec-Avant military satcom antennas if you want the real thing. Even a recent Ebay D&M fold up at $295 is not bad considering the price of a new one, see item # 130106616100. The Timestep yagi claim of 10dB over a Discone may be true but the UHF mil satellites are circular polarity (right hand) and the Timestep yagi will take an immediate 3dB hit in gain due to the linear vs circular pol incompatibility. If you are handy with tools you can easily make a 5 to 10 turn helical antenna using wood or PVC pipe for the support and ¼” copper tubing or even bare copper wire for the “spring”. You should not need a preamp with most of the tactical/portable mil antennas or a home made helical unless your feedline loss gets out of hand. Another antenna to consider is a surplus aircraft satcom antenna, which shows up on Epay quite often. These will need a sheet of metal or screen about 2ft square under them and probably a pre amp. One nice thing about these is you don’t have to point them anywhere specific. Most models also have additional innards and a second connector to support normal VHF and UHF mil air bands. I have one model that covers 30 to 400MHz in one mode and 225-400 circular pol for satcom. The other here one covers satcom and at least VHF air but I need to sweep it to find out just how far it goes. I didn’t pay more than $50 for either of these aircraft antennas on Ebay.
prcguy

 

[mancow]

word




The Trivec Avant (Dorne and Margolin) DM-120 foldout works very well.

 

[qc]

Thanks for all the help

 

[spiritwolfpr]

Hello Friends:

I'll like if possible if any one can tell me how to make a unexpencive
UHF satcom antenna

Thanks!!

 

[N1JFU]

I've been using this to monitor milsats:

http://www.dpdproductions.com/page_miltenna.html

It's been great so far, but I am also using an ARR pre-amp.

-Steve

 

[SteveDouglass]

Dit satcom antenna

I've begun posting parts of an article on how to build your own DIY UHF SATCOM antenna on my blog at: Black Horizon: How to build a $5,000 dollar UHF SATCOM antenna for under $20 Part 3

OnceI have finished posting it- I will edit it and post it on this forum (as one article) for downloading as a .pdf.

I hope you enjoy the read and it helps!

-Steve Douglass

 

[prcguy]

Hey Steve,
I noticed your website has at least two of my copyrighted pictures on the home page, the one showing a collection of satcom antennas and the closeup of the folded dipole from the collection.

Please remove these pictures from your site immediately or PM me to discuss some rules for using them.

You might also check the March and July 2010 issues of Monitoring Times magazine for an inexpensive UHF satcom antenna project.
prcguy

I've begun posting parts of an article on how to build your own DIY UHF SATCOM antenna on my blog at: Black Horizon: How to build a $5,000 dollar UHF SATCOM antenna for under $20 Part 3

OnceI have finished posting it- I will edit it and post it on this forum (as one article) for downloading as a .pdf.

I hope you enjoy the read and it helps!

-Steve Douglass

 

[BMT]

The best homebrew SAT antenna I have seen cost less then $10.00 to build.
It's been field tested in A-stan and Iraq.
This antenna will fit in a sandwich bag.

BMT

 

[prcguy]

Is that the one that has two loops, one sitting above the other?

If so its not a good idea to use for anything other than listening, which it does very poorly. If you were in the boonies with a broken satcom antenna and had to make one to save a life that would be something, but that antenna is being touted as a replacement for an actual satcom antenna, which its not.

The "inventor" is trying to use a very narrow band full wave loop to cover both uplink and downlink frequencies which it cannot do without serious compromise. Then there is the issue of the linear polarized loop being used with a circular polarized satellite. That's a -3dB hit in performance right there. Then the spacing being used or recommended between loops is far from optimum.

The worst portable military satcom antenna on the market that I know of is rated around 5dBic gain, or 5dB above a circular polarized isotropic antenna. The special forces thing is immediately 3dB down from that or about 2dBic gain because of the linear to circular problem. With all the other compromises in the special forces DYI antenna it would be a miracle if it even reaches 0dBic gain.

Oh, but the guys in the field report it works great.......Yea, and I can get a usable satcom signal holding my police scanner with stock rubber duckie antenna sideways above a car hood and it receives UHF satellites. That doesn't mean its worth writing up and selling as a viable satcom antenna.
prcguy

The best homebrew SAT antenna I have seen cost less then $10.00 to build.
It's been field tested in A-stan and Iraq.
This antenna will fit in a sandwich bag.

BMT

 

[SteveDouglass]

Hey Steve,
I noticed your website has at least two of my copyrighted pictures on the home page, the one showing a collection of satcom antennas and the closeup of the folded dipole from the collection.

Please remove these pictures from your site immediately or PM me to discuss some rules for using them.

You might also check the March and July 2010 issues of Monitoring Times magazine for an inexpensive UHF satcom antenna project.
prcguy

The photos have been removed. I didn't mean to step on your toes.

 

[eorange]

Steve, looking forward to the construction details. Your column in Pop Comm was my all-time favorite!

 

[SteveDouglass]

Thanks!

Steve, looking forward to the construction details. Your column in Pop Comm was my all-time favorite!

I enjoyed
both Pop Comm and Monitoring Times. I quit Pop Comm because they didn't pay me - and it took them almost two years to catch up.

As for MT - some on the editorial staff thought my column was too controversial. They even ( and I don't believe it) say they were threatened by an IRS audit if They kept me on. I really don't know what the truth was.

Nowadays - I write for just me- on my blog and take the occasional free-lance job.

I hope you enjoy the rest of the SATCOM article. Again- sorry for snarfing copyrighted photos. I found them on Google Images and didn't know who they belonged to. I guess I should have asked!

 

[SCPD]

Guys..I was just wondering if you were to make such an investment in time building one of these antennas or buying one of these antennas what can you actually hear on them? Is it mil com data that you would be able to receive or voice comms? What sats are you picking up on these systems and what freqs are they operating on? In short is it worth the trouble building one of these antennas?

 

[prcguy]

Most of the traffic is encrypted and probably 99.9%. However, there are pirates on the satellites every day and an occasional clear transmission from supply aircraft going to Antarctica plus the very rare screw up where someone thought they were encrypted but were not.

For the military monitor enthusiast receiving signals from space is one of the more exciting facets of the hobby.

You might Google search for frequency lists from Larry Van Horne or others to see whats out there.
prcguy

Guys..I was just wondering if you were to make such an investment in time building one of these antennas or buying one of these antennas what can you actually hear on them? Is it mil com data that you would be able to receive or voice comms? What sats are you picking up on these systems and what freqs are they operating on? In short is it worth the trouble building one of these antennas?

 

[brandon]

Guys..I was just wondering if you were to make such an investment in time building one of these antennas or buying one of these antennas what can you actually hear on them? Is it mil com data that you would be able to receive or voice comms? What sats are you picking up on these systems and what freqs are they operating on? In short is it worth the trouble building one of these antennas?

I'm a total noob when it comes to satcom monitoring and in the same boat. I recently picked up a surplus antenna off eBay, so figured it would be worth giving it a shot. So far in my very limited monitoring the only voice activity I have logged are from Portuguese speaking bootleggers. 255.550, 262.225, 252.150 are some freqs with activity of this nature. I can also hear data bursts on 262.275 and occasional encryption on 261.575. Hopefully soon I'll get around to doing some unattended logging/recording and have a better understanding of what is available to monitor.

 

[BMT]

Would you spend a few thousand dollars just to monitor somewhere between 300 and 400 freqs?
Plus the software I have seen used, it's a waste of money.