MD UES Reception w/ yagi....

[doctordave]

Folks,

Using just the famed RS 800 portable antenna, I can typically just barely get the control channel for the UES Consortium 800 digital system to break squelch up in Northern Balt County...the radio is on the second floor of my house. On some days - fair reception. I am wondering how helpful an 800 MHZ Yagi antenna (for example, rfwiz.com has one rated for "6 db" gain"), mounted at about the same height with only several feet of appropriate low-loss cable (or perhaps 8 feet higher, in my attic) would be at improving the reception. The big catch is that there are a great number of 800 MHZ pager/cell towers in between me & the public safety towers on the Shore....I am wondering if that simple fact will all but kill my chances of seeing much benefit w/ the yagi. Any thoughts on this? Would be nice to avoid springing 50-75 bucks if the project is a huge stretch. Anyone else up this way monitoring the UES system?

Appreciate any responses....or perhaps ideas on other approaches.

Dave

 

[ka3jjz]

Folks,

Using just the famed RS 800 portable antenna, I can typically just barely get the control channel for the UES Consortium 800 digital system to break squelch up in Northern Balt County...the radio is on the second floor of my house. On some days - fair reception. I am wondering how helpful an 800 MHZ Yagi antenna (for example, rfwiz.com has one rated for "6 db" gain"), mounted at about the same height with only several feet of appropriate low-loss cable (or perhaps 8 feet higher, in my attic) would be at improving the reception. The big catch is that there are a great number of 800 MHZ pager/cell towers in between me & the public safety towers on the Shore....I am wondering if that simple fact will all but kill my chances of seeing much benefit w/ the yagi. Any thoughts on this? Would be nice to avoid springing 50-75 bucks if the project is a huge stretch. Anyone else up this way monitoring the UES system?

Appreciate any responses....or perhaps ideas on other approaches.

Dave

If the direction of the beam needs to go thru the Towson/Timonium corridor, forget it. It's a good haul from Northern Baltimore county to the Eastern shore; I'm surprised you're getting anything at all.
Yeah, all those thrice-xxxxx pager and business broadcasters (not to mention a few TV microwave links in the area) is going to desense you to death, I'm afraid. (Depending on where you are in Northern Baltimore county, of course). The extra height will both hurt and help you; you will pick up more, but you might also 'hear' more of the junk, too.

Methinks you'd be better off pointing your way NNE; with the Harford system still in testing stages, plus Delaware (which is online) and Cecil county (still have heard nothing about this system), I think you'd have better luck with those.

Sri about that...Mike

 

[doctordave]

Mike,

Thanks for your thoughts on this. I am also surprised at what I'm getting from the UES system....sadly, nothing but hiss on the DE system channels (as would be expected). I actually have one of Larry's (from BNC antenna) 2-2067 high gain 800 antennas....might just try converting that to base and see what happens.....omni may be as good as directional in this application, because the bulk of the RF garbage is directly between me and the UES towers. We shall see. A bit of a gamble, but fortunately a very inexpensive one. I'll let you know how it works out.

Dave

 

[ka3jjz]

Dave - there's a couple of facts you need to remember. Lots of people assume that a 800 mhz signal will travel the same distance as a VHF hi band signal of equal power. Not so - the 800 signal will have a much shorter range, due to the shorter wavelength (getting closer to the wavelength of light the higher you go), loss factors and terrain. The inverse square law works the same way here as it does on a beam of light - so it's much harder to hear the UES system, even with a partial water path.

The other thing to keep in mind is the gain figures - any gain figure that doesn't give you a reference point (dbi is one favorite - db over an isotropic - that is to say one that radiates well in all directions, which basically doesn't exist) should immediatly be suspect. A 6db gain antenna (under the best of conditions) will increase your received signal by 4 times (3db gain is double the signal). That means 4x the junk along with the stuff you really want to hear. If your scanner isn't capable of handling the higher signal levels, intermod and desense will be the likely result. On HF it's quite a bit different.

Sometimes less is really more. 73s Mike