Extending Antenna - Page 2

nobb · 05-19-2007, 09:00 PM

For an antenna, isnt the length important? I remember I designed an fm transmitter before, and the site mentioned that for the transmitter to work best, the antenna had to be of a specific length. The length was calculated based on the frequency that would be used.

http://k4far.home.att.net/calc.html
http://www.qsl.net/kd4sai/antencal.html

jschrauwen · 05-19-2007, 09:43 PM

Look at post #8.
As long as it's for the frequency required. In this case 2.4GHz. There can be all sorts of sizes and shapes.
I'm interested mostly in the correct connectivity and the proper selection of a 2.4GHz antenna with it's specific connector termination that will marry up with a corresponding U.FL pigtail bulkhead cable to the card.

BarryWoods · 05-20-2007, 02:49 AM

You'll want rp-sma. It's the one with the pin in the center and not the port for the pin. That antenna is going to need some type of metal ground plane to work correctly. They are made to use the roof of your car as one. Here's a pretty good site for wifi antenna info.

http://wireless.gumph.org/

I made it as far as Oman, try to stay in the shade as much as you can, it's freaking hot over there...

jschrauwen · 05-20-2007, 09:25 AM

Quote: Originally Posted by BarryWoods

You'll want rp-sma. It's the one with the pin in the center and not the port for the pin. That antenna is going to need some type of metal ground plane to work correctly. They are made to use the roof of your car as one. Here's a pretty good site for wifi antenna info.
http://wireless.gumph.org/

I thought the RP-SMA was the correct match.
Thanks for the link as well. I think you posted that one before somewhere else

. OK, Perhaps a re-thinking of this. Is it 100% the norm that all magnetic bases require that metal plane source as part of it's frequency matching properties to get good reception. I saw a number of interior antennas that also have a magnetic base, so does this still apply? Maybe it's best to state my intentions and then yourself or someone could enlightnen me as to viable antenna options.
I'm hoping to have the antenna predominantly inside the car at all times. Perhaps in the rear hatch/deck. That said, I'll still leave myself the option (if required) to move the interior location of the antenna to the exterior (while parked). I'm not that concerned about having reception on the fly, rather when parked somewhere.
There are these type;
http://www.hyperlinktech.com/web/hg2403cu.php
An interior (ceiling mount) omni-directional antenna that I could have sitting in the rear hatch or deck and then set out on top of hatch or roof when stationary.

OR;
http://www.hyperlinktech.com/web/hg2408p.php

OR;
http://www.hyperlinktech.com/web/re05u.php
This one is meant for interior or exterior use. It's not too obtrusive and is only 6" high which means it could easily be plunked in the rear hatch/deck or even slipped outside and mounted to the outside of the rear hatch (if needed). The only short-coming to this antenna is that it only comes with a 4' length of cable. I would need to either request the vender to extend the cable length to about 10' (normal lengths as seen in other antennas) or introduce an intermediate cable to give me the dsired length.

As you can see, I'm not going to get fussy with cost as most antennas seem to be around $30 or less. Cheapest is not the deciding factor here, rather, quality, efficienccy and effectiveness is the goal.
I hope this helps for those trying to discern what I'm looking for.

Quote: Originally Posted by BarryWoods

I made it as far as Oman, try to stay in the shade as much as you can, it's freaking hot over there...

Thanks Barry

. My 6 months will be in Kandahar working in flight operations. Should be OK if the AC works

. Your not an AWACS guy or scope-dope are you?

BarryWoods · 05-20-2007, 01:49 PM

Quote: Originally Posted by jschrauwen

I thought the RP-SMA was the correct match.
Thanks for the link as well. I think you posted that one before somewhere else

. OK, Perhaps a re-thinking of this. Is it 100% the norm that all magnetic bases require that metal plane source as part of it's frequency matching properties to get good reception. I saw a number of interior antennas that also have a magnetic base, so does this still apply? Maybe it's best to state my intentions and then yourself or someone could enlightnen me as to viable antenna options.
I'm hoping to have the antenna predominantly inside the car at all times. Perhaps in the rear hatch/deck. That said, I'll still leave myself the option (if required) to move the interior location of the antenna to the exterior (while parked). I'm not that concerned about having reception on the fly, rather when parked somewhere.
There are these type;
http://www.hyperlinktech.com/web/hg2403cu.php
An interior (ceiling mount) omni-directional antenna that I could have sitting in the rear hatch or deck and then set out on top of hatch or roof when stationary.

OR;
http://www.hyperlinktech.com/web/hg2408p.php

OR;
http://www.hyperlinktech.com/web/re05u.php
This one is meant for interior or exterior use. It's not too obtrusive and is only 6" high which means it could easily be plunked in the rear hatch/deck or even slipped outside and mounted to the outside of the rear hatch (if needed). The only short-coming to this antenna is that it only comes with a 4' length of cable. I would need to either request the vender to extend the cable length to about 10' (normal lengths as seen in other antennas) or introduce an intermediate cable to give me the dsired length.

As you can see, I'm not going to get fussy with cost as most antennas seem to be around $30 or less. Cheapest is not the deciding factor here, rather, quality, efficienccy and effectiveness is the goal.
I hope this helps for those trying to discern what I'm looking for.

Thanks Barry

. My 6 months will be in Kandahar working in flight operations. Should be OK if the AC works

. Your not an AWACS guy or scope-dope are you?

Naa, I was a KC-135R crew chief. I've actually had pretty good luck with one of those blade style antennas. I had it velcrowed to my powerbook display. The ceiling mount antennas have the pigtail coming straight out of the bottom, would be kinda hard to sit on anything without drilling holes. If it was me, I'd just pick up a 6 or 8 dbi rubber duck for the trip and get a mag mount once I got back.

jschrauwen · 05-20-2007, 05:58 PM

Quote: Originally Posted by BarryWoods

Naa, I was a KC-135R crew chief. I've actually had pretty good luck with one of those blade style antennas. I had it velcrowed to my powerbook display. The ceiling mount antennas have the pigtail coming straight out of the bottom, would be kinda hard to sit on anything without drilling holes. If it was me, I'd just pick up a 6 or 8 dbi rubber duck for the trip and get a mag mount once I got back.

Crew Chief eh? - NICE!!!
I've controlled and done a number of PAR approaches on that AC pattern. They used to come up (mostly overfly) fairly often to CFB Comox, BC (Vancouver Island) and then let them do their thing in their AR doing AAR with some of our F18's and F101's way back when. GO AIR FORCE

Just ordered the RP-SMA type U.FL pigtail and rubber duck antenna (9dBi) from these guys online - http://www.sharperconcepts.net/
We'll see how that goes when I bench test them. *fingers crossed* I got it right. Many thanks Barry, cheers,
John

jschrauwen · 05-28-2007, 09:32 AM

Many thanks again Barry
I got the correct U.FL pigtail which I attached to the "Main" connector on the card and the bulkhead fitting worked just fine on my Travla case. I ended up getting two antennas. The rubber duck type that easily attached to the bulkhead fitting and this one;

which comes with a 10' lead of cable and RP-SMA fitting as well. So I can use this one for the car - either in the rear deck or mounted on the outside when parked. An extra bonus was that the rubber duck RP-SMA antenna will attach to the magnatic base of the second antenna as well. Nice to have a few options if necessary. Again, many thanks for your assistance in this as it's always a steep learning curve for this noob.
Now, on to the next project - finding a webcam for my car pc that has an integrated microphone. Strange that I haven't found one thread on this unless my search parameters are flawed.
Cheers mate,

John

GO AIR FORCE

jschrauwen · 07-30-2007, 11:21 AM

After many successful months in this config (not installed in car asa of yet) I decided to take my car PC with me on deployment to Kandahar, Afghanistan.
From my hootch (tent) I can pick a lot of open sources. What's unique is that in my general tent vicinity other laptop users are unable to cature any signal from the Canadian source, whereas I have no problems. This is by using the rubber duck antenna only. So any posts you see of mine til next January will be from my "hootch" (tent) via my CarPC.

BarryWoods · 07-30-2007, 09:09 PM

Quote: Originally Posted by jschrauwen

After many successful months in this config (not installed in car asa of yet) I decided to take my car PC with me on deployment to Kandahar, Afghanistan.
From my hootch (tent) I can pick a lot of open sources. What's unique is that in my general tent vicinity other laptop users are unable to cature any signal from the Canadian source, whereas I have no problems. This is by using the rubber duck antenna only. So any posts you see of mine til next January will be from my "hootch" (tent) via my CarPC.

Sweet! Glad it's working for you. Hopefully it's a bit cooler for you there. I was a tad further south. Pic was taken at Thumrait airbase in Oman, at 9:45am...