Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: New to VHF satellites/what kind of antenna ???  (Read 14916 times)
KC8Y
Member

Posts: 240




Ignore
« on: September 18, 2013, 09:13:13 AM »

I am very new to satellites-just want to receive transmissions, only.  Have a Baofeng5R
(covers 2m & 440) and a IC-7410 xcvr (which I can also use a convertor; to receive all modes in use).  Interested in the 440 band, mostly.

My biggest problem: What is the simplest & best antenna (forindoors use in the basement of house) I can receive on Huh  [Arrow Ant. hand beam, M2 eggbeater,  M2 HQ loop, Huh]

I'm handicapped-cannot go on roof, DARN !!!!

Ken KC8Y

Logged
K6LCS
Member

Posts: 1514


WWW

Ignore
« Reply #1 on: September 18, 2013, 02:44:19 PM »

Forget the eggbeaters - you want some gain.

The Elks and Arrows cost about $115 each. A tape measure beam will set you back
about one hundred dollars LESS than that.

Antenna ideas for working the sats posted on the ANTENNAS page at ...

http://www.work-sat.com

Clint K6LCS
Logged

Clint Bradford, K6LCS
http://www.k6lcs.com
G8YMW
Member

Posts: 219




Ignore
« Reply #2 on: September 20, 2013, 08:42:48 AM »

Ken, I'm not sure if I'm reading your post right but an aerial in the basement, particually on 70 cms is not going to work very well.
(My apologies if I am wrong)

Tony
Logged

73 details Tony
Sent by WW2 Royal Navy signal lamp
KC8Y
Member

Posts: 240




Ignore
« Reply #3 on: September 21, 2013, 05:33:42 AM »

Tony thank you for the response...I think you're correct about the 440 band...

Think I'm gonna try getting a 70cm antenna (omnidirectional) mounted on the roof-with help from my brother; also willing to try a convertor, for 70-cm, on the HF unit.

Ken KC8Y
Logged
K6LCS
Member

Posts: 1514


WWW

Ignore
« Reply #4 on: September 21, 2013, 06:15:01 AM »

I thought you said you were interested in satellite work ... An omni-directional antenna is
not what you want. You want some gain ...

Clint K6LCS
Logged

Clint Bradford, K6LCS
http://www.k6lcs.com
KC8Y
Member

Posts: 240




Ignore
« Reply #5 on: September 21, 2013, 09:37:56 AM »

In the beginning,  I said "...just want to RECEIVE satellites..." not interested in working any.

I do not have time, expensive equipment or the ability.

Ken KC8Y
Logged
K6LCS
Member

Posts: 1514


WWW

Ignore
« Reply #6 on: September 21, 2013, 10:02:37 AM »

You have me totally confused. You started out mentioning expensive commercial antennas ... I reply with a $15 solution ... and a Web page full of recommendations ...

I guess all I can say is the sats are weak signals from upwards of five hundred miles away. Verticles and eggbeaters are not the way to go.

Logged

Clint Bradford, K6LCS
http://www.k6lcs.com
G8YMW
Member

Posts: 219




Ignore
« Reply #7 on: September 21, 2013, 04:31:07 PM »

My thoughts,
A crossed dipole array or 2XY fixed pointing vertically as a starter array
Make sure you have the best coax you can lay your hands on to make sure you get as much signal into the shack as you can.
Later (If you find that this is your "barrow") a yagi angled about 30/45 degrees and a rotator.

Disclaimer, I have never used  satellites however I am a V/UHF man

Cheers
Tony
Logged

73 details Tony
Sent by WW2 Royal Navy signal lamp
K0JEG
Member

Posts: 650




Ignore
« Reply #8 on: September 22, 2013, 08:50:19 AM »

In the beginning,  I said "...just want to RECEIVE satellites..." not interested in working any.

I do not have time, expensive equipment or the ability.

Ken KC8Y

Receiving ham band sats with an omni is an exercise in futility. Most omni antennas are not going to have enough gain to hear any of the LEO ham sats (or much else in the sky). A vertical with gain (such as a collinear, commonly used in base stations) will be a poor choice because they tend to have a donut-shaped reception pattern favoring the horizon. For satellite reception you really want a somewhat directional antenna such as what Clint suggested. A tape-measure beam can be constructed for a few dollars and for receive-only is certainly not fussy when it comes to construction.

Here is a good example of the costs for building your own:
http://www.harborfreight.com/12-ft-x-12-uikfind-tape-measure-69097.html - $1.49
http://www.radioshack.com/product/index.jsp?productId=2103481 - $7.99
http://www.homedepot.com/p/36-in-x-1-in-Poplar-Square-Dowel-1-3HWSQED/202287699?MERCH=REC-_-nosearch3-1-_-NA-_-202287699-_-N#.Uj8OVBZeXlJ - $3.50.

Now, you stated you're handicapped and cannot go out on the roof. But the nice thing about this setup is you only need to get as far as the back yard and you should be able to use this for monitoring and later on transmitting if you get the bug. If you cannot hold the antenna and radio at the same time, a 6 foot piece of PVC pipe and creative use of even just duct tape should allow for supporting the antenna. If we knew more about your handicap I'm sure we could all come up with a few ideas (wheelchair mounts? Armstrong rotators?).

Is it a permanent installation that can be used on a whim? No. But can it be set up and used fairly easily without a lot of set-up time? Absolutely. I would guess that most people who mess around with satellites have had success with a tape measure beam, and many people use that and nothing else. Once you start wanting to do a permanent installation the costs go up dramatically.
Logged
K6LCS
Member

Posts: 1514


WWW

Ignore
« Reply #9 on: September 22, 2013, 09:56:26 AM »

>> ... satellites..." not interested in working any. I do not have time, expensive equipment or the ability ...

I think we're on different wavelengths ...

You already have a radio capable of working ham satellite SO-50. Just improve the antenna a little bit,
and YES, you can work a bird with equipment you already own.

You can also monitor the ISS' packet transmissions as it streaks overhead. Even without having packet
decoding software/hardware and just using your HT, this can be cool, too.

All the info you need to actually work SO-50 with the HT you already own is posted at ...

http://www.work-sat.com

YES - people are WORKING SO-50 with as little as a $15 antenna and dual-band HTs!*

Clint K6LCS

* - It is really preferable to work SO-50 in "full duplex mode," where you can monitor the
downlink (earpiece) while you are keying your mic. A second radio - or a scanner - could be
that second radio. Not absolutely mandatory, but preferable to work full-duplex.
Logged

Clint Bradford, K6LCS
http://www.k6lcs.com
N4UFO
Member

Posts: 197




Ignore
« Reply #10 on: September 23, 2013, 02:20:54 AM »

Hi Ken,

When I decided to get back on satellites again I had a 2m FM radio capable of 10 watts and a 2m squalo (horizontal omni) on the roof for transmit and purchased a Baofeng UV-3R for receive. I built a 'CJU antenna' with several feet of 12 gauge solid copper wire, a short piece of scrap pex pipe and a leftover end of a cable that had a BNC and RG-178 coax on it. (Coax used was only a few inches long) Antenna plans: http://personales.ya.com/ea4cax/paginaea4cyq/cju/cjuingles.pdf

I sit in my ham shack and work SO-50 with this setup... In fact, the CJU antenna mounted directly on my HT receives better at most times than the 7 element yagi I have mounted outside on a rotor; because the outside antenna is at fixed elevation and polarity. The important part of receiving SO-50 is the ability to aim and twist the antenna AND a very short piece of coax between the antenna and the receiver. (Or the antenna and a preamp.) Hearing SO-50 on an omnidirectional antenna... pretty much impossible. It has an ERP of 1/4 watt, hundreds of miles away and the satellite tumbles constantly changing the polarity of the signal.

The only other UHF downlink bird is FO-29... The other two current voice satellites are AO-7 and VO-52. AO-7 alternates between 2m and 10m downlink changing once a day. You can try listening to the 10m downlink with your HF rig, but there is not much activity. All the satellites planned to be launched in the near future are will all be 2m downlinks. And they will all be SSB/CW birds. You speak of using a converter... a lot would depend on that. I had trouble finding any useful converters for satellite when I started looking. I ended up with a single band all mode radio but quickly upgraded to an FT-847 which is designed for satellite. BUT that aside... a directional antenna held in the hand and aimed yourself will be FAR SUPERIOR to any omnidirectional antenna mounted on the roof. One, the gain. Two, less coax loss; a VERY big deal. Three, ability to compensate for tumble.

Guys are working satellites all the time with an HT and an Arrow antenna. Guys are working satellites with Yaesu FT-817s and an Arrow all the time. Two radios allowing you to receive your own signal while transmitting is the norm, a single radio is workable but has problems and is more likely for you to cause QRM. Guys do work satellites with eggbeaters and preamps, but they are also known as the guys who can't hear squat. They spend a lot of time saying, 'Who is that calling? Can you repeat your callsign?' A vertical or other omni might be acceptable for transmit even at 5-10 watts, but NOT receive.

Bottom line... if you insist on putting up an omnidirectional antenna, at the very least plan on a GOOD preamp and low loss coax, i.e. LMR-400. And then do not have high expectations. An Arrow would be far better... there are many pictures out there of antennas being hand held or mounted on tripods and they work much better than something on the roof. You don't NEED something on the roof... this is not terrestrial VHF/UHF, you are aiming into the sky. The only time height above ground is an advantage is if you want to try working passes that are close to the horizon and need to get above neighboring obstacles. With sats, far more important to be able to get away from obstructions like trees than to have height. In my case, my house is one story and a wooden roof; I sit in my hamshack chair and hear just fine. (I've seen a lot of installations with rotatable directional antennas mounted inside attics, by the way.) From your basement... would depend on the construction of the house. But with an HT, maybe you can go out on a patio or even try from upstairs.

If you don't want to buy, try building... here are a couple of designs:

http://www.wa5vjb.com/references/Cheap%20Antennas-LEOs.pdf
http://www.amsat.org/amsat-new/information/faqs/crow/

That second one is designed for even non hams and is made from cardboard and copper wire... THAT will be better for receiving UHF downlink birds than an omni on your roof... even with the latter using a preamp and low loss coax. - To quote Kevin Bacon in a Few Good Men, "These are the facts and they are not in dispute."   Cheesy  And please understand, no one is trying to be antagonistic, we have simply watched a lot of people try the 'omni on the roof' and waste a lot of time and effort... AND many go on to cause interference because they keep calling over the satellites causing QRM and don't know it because they can't hear the downlink.

When you get ready to try tracking and receiving the satellites, post a note over in the satellite forum and someone can recommend a program or a free website to help you do that.

73 es GL!

Kevin N4UFO
« Last Edit: September 23, 2013, 02:25:01 AM by N4UFO » Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!