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AirNav Systems Forum

AirNav Radar => AirNav Radar Discussion => Topic started by: Johnn on February 01, 2010, 05:08:43 PM

Title: Im thinking of buying a pre-amp, will I see much difference?
Post by: Johnn on February 01, 2010, 05:08:43 PM
Hi There,
I was thinking of buying this pre-amp - http://www.airbandonline.co.uk/viradac_jim75pl.htm

however has anyone found these a good product? At the mo I have a okay 60 mile all around me, however would a pre-amp increase range/contacts, like it says on the link?

Many Thanks
John
Title: Re: Im thinking of buying a pre-amp, will I see much difference?
Post by: Dean on February 01, 2010, 05:28:10 PM
A pre amp should be placed as near to the antenna as is possible, if it isn't then any signal lost in the cable can't be amplified. This unit certainly doesn't look water proof / resistant so would only be able to be fitted say in a loft on an internal antenna. Another concern is the wide frequency response, again not saying it won't work but I use the WiMo sealed unit specifically centered on 1090.

There are other threads where you will get a 50/50 split between the yes they are good and no they aren't.

If there is no signal reaching the antenna then no pre amp in the world will help.

Concentrate on getting a hi dB gain antenna as high as possible in the open for best results. Adding a pre amp to that MAY give you some benefit.

Hope that helps.
Title: Re: Im thinking of buying a pre-amp, will I see much difference?
Post by: EMA on February 01, 2010, 06:13:09 PM
I agree with Dean you cannot amplify what is not there with a wide band pre-amp you will only increase the noise.

There is no substitute for a good aerial in the right location and the correct coax and connectors.
Title: Re: Im thinking of buying a pre-amp, will I see much difference?
Post by: tarbat on February 01, 2010, 07:09:52 PM
In my opinion, getting the antenna as high as possible is most important, and the pre-amp can then be used to overcome the signal loss down the long antenna lead you will then need.
Title: Re: Im thinking of buying a pre-amp, will I see much difference?
Post by: Johnn on February 01, 2010, 07:13:32 PM
Thanks for the replys, I may look into extending the height of the antenna, at the mo it is on a 12t pole.Thanks for the help everyone.
Johnn
Title: Re: Im thinking of buying a pre-amp, will I see much difference?
Post by: G0HWC on February 02, 2010, 07:26:33 AM
I have some screen shots of what changed with new hi gain antenna
when I first gor my ANRB here:
http://www.g0hwc.com/airnav_setup.html

Paul
Title: Re: Im thinking of buying a pre-amp, will I see much difference?
Post by: radarspotter10 on February 02, 2010, 08:16:08 AM
Quote from: Johnn on February 01, 2010, 07:13:32 PM
Thanks for the replys, I may look into extending the height of the antenna, at the mo it is on a 12t pole.Thanks for the help everyone.
Johnn
Hi johnn.
Any radio ham will tell you height is might.
from pat
Title: Re: Im thinking of buying a pre-amp, will I see much difference?
Post by: CoastGuardJon on February 02, 2010, 02:15:41 PM
Hi Johnn, I'm getting a distinct feeling of deja vu here!

http://www.airnavsystems.com/forum/index.php?topic=3815.msg37883#msg37883

Nothing has changed!!!
Title: Re: Im thinking of buying a pre-amp, will I see much difference?
Post by: Johnn on February 02, 2010, 04:12:57 PM
O dear, I dont want memory loss at my age.. lol
Thanks for the link
Johnn
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