post your maximum miles on UHF

[ridgescan]

I run a Diamond d130j for the scanners. The furthest copy with understandable voice I can get at 400-500mhz is 25 miles. My concern is UHF. Given all the hills around here I consider that distance pretty good. Do you guys agree? I would like to hear from those here who have hilly terrain to deal with what is the furthest you can get good voice copy in the UHF range, and what antenna you run.
Also, I have been eyeing the Austin Ferret base antenna. Do they still make it? Does anyone here have experience with it? I am impressed with the idea that it is a multiband as opposed to wideband, and am wondering if it would get me even more range than the d130j.

 

[n5ims]

Google shows some places that appear to currently be selling the Austin Ferret for about $250 or so. It's basically just a multi-band vertical dipole antenna so it won't have much gain. It will provide a better match on the various bands than a Discone like the D130, but probably wouldn't provide much more range.

If you only care about UHF, your best bet would be to get a UHF only antenna, possibly with some gain. These shouldn't be too hard to find. You can easily find dual-band ones that provide good VHF-Hi and UHF coverage for much less than the Ferret as well. Search for a dual band ham antenna and you'll find several to select from. Texas Towers, Comet GP-9 Page will give you 11 dB on UHF and 8.5 on VHF-Hi.

What you might do is get one like I posted for one scanner for some coverage and use the D130 on the other for other bands. You'll get rid of the loss from the splitter with a setup like that as well.

 

[kruser]

I run a Diamond d130j for the scanners. The furthest copy with understandable voice I can get at 400-500mhz is 25 miles. My concern is UHF. Given all the hills around here I consider that distance pretty good. Do you guys agree? I would like to hear from those here who have hilly terrain to deal with what is the furthest you can get good voice copy in the UHF range, and what antenna you run.
Also, I have been eyeing the Austin Ferret base antenna. Do they still make it? Does anyone here have experience with it? I am impressed with the idea that it is a multiband as opposed to wideband, and am wondering if it would get me even more range than the d130j.

I bought the Ferret and was highly disappointed with the performance.
I knew it was not a gain antenna but figured it would work as well or slightly better in some bands over the Diamond D130. It did not. I did tests comparing the Ferret as well as several other antennas.

The Ferret came in last on every test frequency in every band except VHF Low.
It sucked badly at 800 and 450. VHF Low was the only band were it had equal performance as my other antennas.

For my tests, I used the same mast, same coax, same height, same Icom R9000 and R7000 along with a slew of active frequencies in all bands as a baseline taken with a discone.

What did work extremely well for UHF 450 was a dual band vertical made for amateur radio use. I tuned it for 150 and 460 instead of the ham bands. The UHF reception from that antenna was superb over all the antennas I tested. In this case, the dual band I tested was a V-42R which I think was a Hy-Gain antenna. That one stayed up for some time but when I got more involved in 800 stuff, it had to go as it did not do well above 480 at all. I do not recall the claimed gain of the V-42R but it was night and day difference in the UHF band when compared to any other vertical "scanner" antenna I tested. It was also superb at VHF High.

Due to the design, it dropped off rapidly when you veered off the tuned frequency range. For example, the civilian air band was almost nonexistent even though I live very close to a major airport.

The Ferret was absolutely horrible at 800 MHz work. I had a better chance at picking up 800 MHz signals with a paperclip stuck in the jack and standing three floors below the roof! The poor performance was not due to overload either. I find the Icom R7000 and R9000 are almost immune to overload or desense when compared to most modern day scanners so they are my primary receivers for everyday use and testing.

I see many reviews of the Ferret and the majority seems to be good so I often wonder if mine was defective as it was the absolute worst performing receiving antenna I've ever used and I've tried a lot.

So if you really want some good UHF reception, do as others have suggested and get yourself a amateur vertical with gain. No quarter waves as they are just unity gain like a discone. If you do not have the space for two antennas then get a dual band like the link someone posted. You should see a large performance gain over the diamond.

Just be aware that they do drop off in performance rather quickly when you get out of the design bandwidth. Some cannot be tuned (most fiberglass) so try and get an aluminum type that you assemble and tune.

Maybe check with the vendor or manufacturer and see if the ones you look at can be set for the frequency of interest. Some can and some can't. Most can though as you will be going higher in frequency in both bands so a shorter antenna is the result. You may have to calculate the element lengths and spacing yourself as many ham antennas only provide a tuning chart for the actual ham bands.

I've always wanted to try a tri-band (6M/2M/440) antenna but I'm not sure if they can be altered enough to cover the three scanner bands without throwing them all out of whack.

Anyone have any advice on tri-banders? Maybe a topic for another thread.

 

[ridgescan]

Great advice n5ims-thanks. You give excellant food for thought-I could dedicate that bc350a to vhf uhf on the dual bander. Wow-impressive gain on that Comet! So that would definately provide even more range than I have now. Would the increase in range be significant enough to pull the trigger?

 

[ridgescan]

Kruzer appreciate your suggestions too. I'm after the tons of agencies out here in the Bay Area that still run on UHF-I hear them off the discone but I want more and cleaner. Plus I want better VHF reception into that bay and out into the ocean for the ships. I want to hear the tanker when it's 25 miles out instead of 10 miles out on the discone. It sounds like that dual bander is the one and I'm glad I asked.

 

[kruser]

One other thing - if you do put up a good gain antenna, it will also pull in the unwanted stuff like that from nearby paging transmitters and other high duty cycle transmitters. I live near several tall hospitals and it seems each one of them has VHF paging transmitters on the rooftops.

The paging signals will wipe out many scanner front ends due to overload and/or intermod or desense. My solution to that was buying some PAR Electronics VHF filters designed for the paging ranges in use here.
They worked fantastic. The 350A is one that will be prone to such interference so try and see how it all works before investing in any filters.
I don't have problems from any UHF systems but PAR makes filters for those common ranges also.

 

[ridgescan]

Yeah I have a ton of pager and cellphone sprouts all around me here in west SF plus power lines so I expect noise . Thanks for the help Kruzer.

 

[wyShack]

For the most part, most monitoring is not distance limited but is limited by line-of-sight issues. In general, 10-15 feet more height and good coax will make more diferance than the differance between antennas. i live in a rural area and don't have much for overload issues.

 

[N5TWB]

Kruzer appreciate your suggestions too. I'm after the tons of agencies out here in the Bay Area that still run on UHF-I hear them off the discone but I want more and cleaner. Plus I want better VHF reception into that bay and out into the ocean for the ships. I want to hear the tanker when it's 25 miles out instead of 10 miles out on the discone. It sounds like that dual bander is the one and I'm glad I asked.

For the most part, most monitoring is not distance limited but is limited by line-of-sight issues. In general, 10-15 feet more height and good coax will make more diferance than the differance between antennas. i live in a rural area and don't have much for overload issues.

wyShack has it right on the height, especially when it comes to receiving ships at a greater distance.

 

[prcguy]

Ridgescan,
I have a well used Comet GP-9N commercial version that has been laying on my roof for a few years and it might be what your looking for. Its 17ft long and rated for 155MHz and 450-470MHz. It works really well on UHF and I never used it for VHF but did check the match and its sharply tuned at 155Mhz.

I think the screw on mast extension that covers the coax connector might be seized and I can't remember if I was able to unscrew the connector or if I just cut the coax off at the base. Either way it needs a little TLC and you can have it for $50 plus shipping.
prcguy

Kruzer appreciate your suggestions too. I'm after the tons of agencies out here in the Bay Area that still run on UHF-I hear them off the discone but I want more and cleaner. Plus I want better VHF reception into that bay and out into the ocean for the ships. I want to hear the tanker when it's 25 miles out instead of 10 miles out on the discone. It sounds like that dual bander is the one and I'm glad I asked.

 

[kb2crk]

as to furthest distance. i have used a repeater from the mobile that was 75 miles as the crow flies.
that was using a motorola maxtrac running 40 watts through a browning 5/8 wave nmo mount antenna.

 

[TroyLynx]

How far can you go?

Maxtrac 450Mhz was a old Memphis school bus radio and a Comet GP-9N on a 60 foot tower on a hill. My wife could talk to me from base to my mobile from Savannah TN to Tupelo MS around 90 miles. If you are needing a long reach antenna I built a 3 element VHF beam for around 10 bucks it has a gain of around 6.8. and a cheap TV rotor. I am hearing police mobiles 60 miles away with good signal. I am working on a PDF drawing on it. message me if you would be interested in the beam info.
Sincerly
Troy H
troylynxtn@yahoo.com

 

[ridgescan]

I appreciate the generous offer prcguy but that long of an antenna would be way obtrusive for this place-I am lucky to get away with something 4' on a 5' tripod. Wyshack you are right about height but I got to watch that too. I have these antennas mounted at the opposite end of where any business would be conducted IE property mgrs so if I go too high or put up something that you would see at a fire station that would be it for this shack. Given the fact that I am getting away with what I am running up there now, I am pretty sure it's simply because I am running on their ignorance for all things radio as it is I guess I should have mentioned my antenna limitations too. Thank you all for the help-so is there nothing better than the d130j but not as large as the GP-9N that us apt guys can really get out with?

 

[ridgescan]

Just an update-I raised my d130j for the scanners up 5' it's now on a 10' mast and now I get all the San Jose Police agencies on the 460s, which are 43-48 miles from here. This discone rocks because IMO given all the hills betweem me and them and I am in the city-that's a good run for a zero-gain shorty like the d130j
I have a question-when it was 5' lower, my randomwire for the HFs ran right past the lower elements only 5" away-could it be that the discone was being phased a bit by the longwire being so close? I just wondered because now it clears that wire by 5' and this drastic an improvement can't be only the 5' rise-or could it? I am getting a good copy on San Jose-3 bars of 6 with good voice!