D130NJ or DPD LP

[co_jim]

I will be receiving my psr500 shortly and currently have a Pro-2006. I live in a 2 story home with no obstructions or higher buildings around me. Due to HOA rules this will be yet another attic install. My attic is metal free and I currently have vertically mounted HD antenna as my only source. I am looking for an antenna and this Diamond series seems to get a lot of good reviews. I am also seeing a lot of the dpd anteannas. I live in Colorado and surrounded by 800Mhz P25 systems (North East to North West) which I want to monitor. I also would like to monitor MilAir with 2 Air Force Bases (North East) and the Airforce Academy (South) within about 30 miles each. So should I be looking at a discone, an LP, or other Omni (OmniX maybe)? My 800Mhz P25 sites are within about 10 miles if that helps. I am also unclear about the N connectors vx the UHF connectors but understand the LMR-400 cable is the way to go, so do I need an adapter from the coax to the radio? Links are appreciated as well. Considering the direction, distance, and bands I'm interested in, I'm also wondering if I should focus on a LP tuned to the MilAir since there's greater distance there with the 800Mhz systems closer or just the opposite LP tuned for 800 or just get an Omni/discone. Ahhhhh my head hurts Thanks in advance for the help.

 

[radiopro52]

I own the DPD LP 118-1000 Mhz antenna, and it's a great performer. But as I've learned, every antenna will have its good and bad points. If you're primarily interested in 800 Mhz, then the DPD 700-1000 MHz UHF LP Antenna might be a good choice. It's specifically tuned to those high bands, so it will be a better choice for listening to those 800 Mhz P25 sites rather than a dual-band or all-band antenna. Also keep in mind that the DPD LP antennas are either semi-directional or directional, which means that it hears frequencies best in the direction that it's pointed. If you have a rotator, that will help big time.

The OmniX is a multi-band antenna just like the LP 118-1000 Mhz antenna. The difference is that the OmniX is...omni. It hears frequencies equally in all directions. But if you know which direction your signals of interest are coming from, which you do, then the LP would be the better choice for a multi-band antenna, in my opinion.

And lastly, N connectors are supposed to be better than UHF connectors (PL-259) because they handle high frequencies better. I have no proof that supports or denies that, so I can't recommend one over the other. But I have read some bad things about UHF connectors, so if you choose to go with a DPD antenna which all have female N connectors on them, then it would be best for you to have a male N connector on your coax, or else you will have to use an adapter like me

Hope this helps.

 

[morfis]

PL259 are not designed for UHF...not really all that good for VHF...they should be regarded as HF and lower connectors.
N-type are fine for the UHF stuff but tend not to be used on budget aerials because they cost more to make.

At 10 miles or so away and given your reasonably unobstructed view then an omni-directional aerial tuned for 800MHz band should be fine. If you want to hear the ground comms from the airfields then a more directional aerial would be better for those BUT not too directional or you'll lose the ability to monitor the aircraft once flying.

A log periodic really needs to be mounted on a rotator - do you have space for the aerial to turn through 360 degrees in your attic? The LP would be quite impractical for aircraft that are moving quickly (unless straight towards/away from you). most aviation comms are fairly brief and rotators are fairly slow

Folded J for the airband stuff, an active aerial combiner (quality type such as Stridsberg) and a tuned 800MHz for that. Decent co-ax and BNC/N-type connectors.....Compact little system that would cover your needs

 

[co_jim]

Some great feedback thank you. Now that I've seen LMR-400 and just how thick this stuff is I'm wondering about how to connect the antenna to the psr500 w/o alot of stress on the radio. I would also like to snake the cable in the wall to and create a connection point there, of course I'm not sure how I would do this. Maybe if I do that then I could use a smaller cable to connect the radio to that junciton? Has anyone done it this way? How you all run the antenna cable to your scanners? I don't really want 10' of cable coming out of my wall that will just be hanging out when I don't have the scanner connected.

 

[radiopro52]

LMR 400 is thick and stiff, but it is bendable to a degree. I'm using 50 feet of LMR 400 coax and I have it running from the feedline of the antenna, down to the ground under the house, and up through the floor to the radio. If you attach the LMR directly to the radio, it can pull it if you have the coax coming to the radio at an angle. But I have the coax coming straight from the back of the radio so it does fine. You can use a few feet of jumper coax to attach to the radio if you want, but remember that the more connectors you add, the more loss.

 

[Paulsan]

Have The Wireman make a patch cable for you from a lighter weight coax to the length that you need and run it from the end of the LMR-400.

http://thewireman.com/

Also check out these guys for the LMR-400.

http://www.bizsyscon.com/viewproducts.php?searchtext=LMR-400

 

[co_jim]

Thanks for all the help. I stopped at HRO today and picked up a Diamond D-130NJ with 25' of 9913 Coax. Our RF engineer at work took care of my N connectors. I just got it hooked up and so far so good. I am picking up a lot more on the air band including a tower that I didn't expect to be able to. Now I'm wondering how much a directional would do. I can see how one might spend a few dollars on antennas. Now I just need my psr500 to arrive.