Scanner for monitoring military aviation frequencies?

a reply to: gariac

The AOR scanners used to have a very high first IF such as that,in fact they were triple conversion as just about all others at that time (20 or so years ago) were only using the more normal double conversion.

originally posted by: Imagewerx
a reply to: gariac

The AOR scanners used to have a very high first IF such as that,in fact they were triple conversion as just about all others at that time (20 or so years ago) were only using the more normal double conversion.

The old ar3000a is great. The only problem is they didn't make enough of them, so they are hard to find used. The AOR handheld scanners weren't so good.

Years ago, the local flea market had stacks of Ar3000a cases. There was some government surveillance project that used PCB from the scanner to make a surveillance system. They junks the cases and one of the PCBs.

I still have an old Yupitero MVT7108, but it needs a supercap replacement.

But as it stands, if you can find an old Pro2042, you are getting a high frequency first IF scanner for under $100. They are also easy to demod tap. The drawback is that you need to program them by hand.

originally posted by: Imagewerx

originally posted by: FredT

originally posted by: Zaphod58
a reply to: FredT

One of my spotter groups was talking about them the other day. They swear by the Uniden 125XLT. I don't know how well it would work out in the wild, but apparently near a field it works really well.

This seems to be the consensus. Any idea if they upgraded the antenna?

Make your own easily enough. A BNC plug (If that's what it uses) and a quarter wavelength whip aerial soldered or crimped into it.At the rough middle of the UHF airband 300 MHz has a wavelength of 1 metre,so the standard 1/4 wave whip aerial will need to be 25cm long.
The claims of gain for aerials like this are rubbish,what is basically a longer aerial wound around a flexible former can't possibly have anything over unity gain.Receiving only aerials aren't as critical for length as they are if you're transmitting through them,but will still work a bit better if they're cut for the band you're listening to.

At least that's how I remember it.Thinking about it some more,have 5/8 wavelength aerials got "gain" over 1/4 wave?

A quarter wave needs a ground plane. A half wave works OK without a ground plane.

originally posted by: gariac
A quarter wave needs a ground plane. A half wave works OK without a ground plane.

Or the other half of the dipole!

originally posted by: gariac

originally posted by: Imagewerx
a reply to: gariac

The AOR scanners used to have a very high first IF such as that,in fact they were triple conversion as just about all others at that time (20 or so years ago) were only using the more normal double conversion.

The old ar3000a is great. The only problem is they didn't make enough of them, so they are hard to find used. The AOR handheld scanners weren't so good.

Years ago, the local flea market had stacks of Ar3000a cases. There was some government surveillance project that used PCB from the scanner to make a surveillance system. They junks the cases and one of the PCBs.

I still have an old Yupitero MVT7108, but it needs a supercap replacement.

But as it stands, if you can find an old Pro2042, you are getting a high frequency first IF scanner for under $100. They are also easy to demod tap. The drawback is that you need to program them by hand.

I had an AOR AR3000 back in the 1980s.It was the first scanner I ever owned that I didn't need to order a new crystal every time I wanted to listen to a different frequency.

originally posted by: Imagewerx

originally posted by: gariac

originally posted by: Imagewerx
a reply to: gariac

The AOR scanners used to have a very high first IF such as that,in fact they were triple conversion as just about all others at that time (20 or so years ago) were only using the more normal double conversion.

The old ar3000a is great. The only problem is they didn't make enough of them, so they are hard to find used. The AOR handheld scanners weren't so good.

Years ago, the local flea market had stacks of Ar3000a cases. There was some government surveillance project that used PCB from the scanner to make a surveillance system. They junks the cases and one of the PCBs.

I still have an old Yupitero MVT7108, but it needs a supercap replacement.

But as it stands, if you can find an old Pro2042, you are getting a high frequency first IF scanner for under $100. They are also easy to demod tap. The drawback is that you need to program them by hand.

I had an AOR AR3000 back in the 1980s.It was the first scanner I ever owned that I didn't need to order a new crystal every time I wanted to listen to a different frequency.

Back when airfone was a thing, the Ar3000a could scan it on frequency. No small feat since you need an offset in addition to an odd step size.

originally posted by: Imagewerx

originally posted by: gariac
A quarter wave needs a ground plane. A half wave works OK without a ground plane.

Or the other half of the dipole!

Yep the ground plane is like a reflector. I don't know the math on a 5/8ths without looking it up.

I've been using a folder dipole for ADSB employing asymmetric elements. That make it easier to reach 50 ohms with a balun. I haven't tried this on milair yet.

originally posted by: gariac
Back when airfone was a thing, the Ar3000a could scan it on frequency. No small feat since you need an offset in addition to an odd step size.

I didn't know about the Airfone thing,but similar to the offset they used to prevent phase cancellation and heterodynes when they had more than one transmitter covering a large area,such as for upper airways? I remember having to tune something like 127.105 to get 127.100 back in the days when I think we still had only 360 channels? I can't remember what the actual offset was though,was it + and - 7.5 KHz?

tower and lots of ANR stuff can be heard on any basic scanner.

milar in the 200 and 300s will need something better but lots of basic (and old/used) scanners will get this.

the BCD436 is great for state-of-the-art but might be overkill (and lots of $) for air monitoring.

I use a BCT 898T and a RS Pro-106, they both work fine.

like lots of things, you can put a lot of $ in if you really want to.

originally posted by: gariac

I've been using a folder dipole for ADSB employing asymmetric elements. That make it easier to reach 50 ohms with a balun. I haven't tried this on milair yet.

I just did a scooby doo confused sound "Aaarug'

a reply to: FredT


It is a desk model connected to an external discone type antenna, but might be set up to be in a vehicle, but my old Uniden Bearcat BC9000XLT is perfect for military UHF (that's AM not FM). They probably don't make it anymore, but mine works fine. There is a military practice area about 80 miles away and I can hear them working out over there easily.

originally posted by: FredT

originally posted by: gariac

I've been using a folder dipole for ADSB employing asymmetric elements. That make it easier to reach 50 ohms with a balun. I haven't tried this on milair yet.

I just did a scooby doo confused sound "Aaarug'

A folded dipole comprised of wire/pipe of the uniform dismeter is 300ohms. A balun has a 4:1 impedance ratio. Hook them up and you get 75 ohms. Most receivers are optimal at 50 ohms. If the diameter of the sides of the folded dipole are different dimensions, you can tweak the impedance. If you shoot for 200 ohms, you get 50 ohms after the balun.

a reply to: ElGoobero

The ground units during Red Flag have appeared on the Nellis trunk system. These include the "MIKE" units that are in the Rolands. You can get a heads up as to the location of aircraft from this channel. This is handy if you are in the range trying to photograph aircraft.

Nellis Trunk

I suppose I should point out the ground units are the enemy and the enemy wants plane targeting information. The idea is the Rolands don't run their radar constantly. That is an easy way to eat ordnance, albeit virtual ordnance. Rather the commander of the ground units tells which Roland to radiate and for how long. Then gives a heads up for targeting. If you are in the range before the Rolands are in position, they will call out their coordinates in lat/lon.

Due to the "affiliation" feature of modern trunk radio systems, you can just monitor them in a "open" mode rather than restricted to various trunk groups. In English, that means the repeater on carries traffic for units that have connected to it. If you are in the boonies, you only hear units in the boonies.

originally posted by: gariac

originally posted by: Imagewerx
a reply to: gariac

The AOR scanners used to have a very high first IF such as that,in fact they were triple conversion as just about all others at that time (20 or so years ago) were only using the more normal double conversion.

The old ar3000a is great. The only problem is they didn't make enough of them, so they are hard to find used. The AOR handheld scanners weren't so good.

Years ago, the local flea market had stacks of Ar3000a cases. There was some government surveillance project that used PCB from the scanner to make a surveillance system. They junks the cases and one of the PCBs.

I still have an old Yupitero MVT7108, but it needs a supercap replacement.

But as it stands, if you can find an old Pro2042, you are getting a high frequency first IF scanner for under $100. They are also easy to demod tap. The drawback is that you need to program them by hand.

Those old AR1000 handhelds where terrible to program, it was like a scientific calculator to program, and took forever to add several channels haha... But they are great wideband radios. I had the AR1000 for decades, after that I went to a AR8000, I'll probably pass on the 8200 because it's not much of an upgrade. Nothing better than a wideband radio.

My favorite RS scanner was the Pro2052, I would access it with a software called Autoit, and program it to do whatever I wanted. The only downside was I had to modify the AM mode for airbands, but that was no problem. It sits on top of my old DX-394. They look good together.

My current scanner is a BCD996P2, I almost took it back, until I updated the firmware and now it's super-fast. I might keep it for another year... because the industry keeps adding trunktracking modes etc.

I plan to sell all my radios and then invest in a IC-R8600.... I always say something like this every-time Icom comes out with a new radio, one day I will follow through.