Receiver site antenna QUESTION
Moderator: Queue Moderator
Receiver site antenna QUESTION
We have an Astro system and there is a tower site we can use for a receiver site but, the antenna's range goes up to 470. Are receivers are in the 474 range. Will this antenna work.? If so how much loss will we have and is there a way to overcome any associated loss..????
Are you using it for receive-only? Then it'll be absolutely fine (negligible loss). If you plan on TXing through it, you need to check the antenna with at least an SWR meter (Bird 43 or comparable) or even better something like an Anritsu Sitemaster.
Assuming this is a quality Decibel/Celwave/etc. antenna, they are rated very, very conservatively. We've got several 150-160 DB224/264s operating at 146 and several 450-470 DB408s running at 448 with no problems whatsoever.
Assuming this is a quality Decibel/Celwave/etc. antenna, they are rated very, very conservatively. We've got several 150-160 DB224/264s operating at 146 and several 450-470 DB408s running at 448 with no problems whatsoever.
You didn't indicate if these antennas are already on the tower and used by others. If your going to use a receiver multi coupler system that is already installed, you might want to check what the bandpass filters are. If this is the case, you will need to probably modify or have to add another set of filters to be able to pass the frequencies your going to use..
If this is a new clean installation, have at it and check for local noise floor levels with a spectrum analyzer. Make sure you don't have some form of interference that may cause you troubles.
Also you should do an intermod study for the site to provide you with a guide before spending any money doing the install. It sure saves time and effort if a hit shows up. At least then you know what your facing.
Jim
[quote="Dover IT"]Yes, they are going to be receiver sites only... Thank You.[/quote]
If this is a new clean installation, have at it and check for local noise floor levels with a spectrum analyzer. Make sure you don't have some form of interference that may cause you troubles.
Also you should do an intermod study for the site to provide you with a guide before spending any money doing the install. It sure saves time and effort if a hit shows up. At least then you know what your facing.
Jim
[quote="Dover IT"]Yes, they are going to be receiver sites only... Thank You.[/quote]
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psapengineer
- Posts: 175
- Joined: Thu Oct 07, 2004 10:00 am
No Problem
Other questions and issues aside, the short answer is, that an antenna that is specified to 470 should work fine for Rx on 474 in a routine application.
You likely won't notice any loss. The out of band antenna, if it is a colinear, big white stick, will exhibit a small amount, less than 1 degree, of "uptilt" that would go un-noticed in most applications since the beamwidth of the vertical pattern is much wider than 1 degree.
Regards, Bob
You likely won't notice any loss. The out of band antenna, if it is a colinear, big white stick, will exhibit a small amount, less than 1 degree, of "uptilt" that would go un-noticed in most applications since the beamwidth of the vertical pattern is much wider than 1 degree.
Regards, Bob