225-400 MHZ ANTENNA

[Saint]

I am looking for a good dedicated 225-400 MHz antenna for the military aircraft, I see also this is good for the 108-136 MHz aircraft band
MilTenna Omni UHF/VHF Military Bands Base Antenna | DPD Productions

And no I do not want to make my own antenna, I am in Canada and would have to change my money over to U.S. So is there any other antenna's I should look at, it will be installed on my 4 floor balcony with my discone antenna.
Steve

 

[prcguy]

A typical scanner Discone like a Diamond 130 series, Radio Shack, Workman, Tram, Icom, etc, are all very good for both VHF and UHF air bands. These are the ones with about 30in radials on the skirt and preferably no whip on top. A basic Discone will give about the same performance across all frequencies on both bands where most any other antenna will have hot spots and not so hot spots across each band.

 

[G7RUX]

In general an antenna tuned for VHF air band will work pretty well on UHF air band as they are harmonically related (second harmonic); this is deliberate so single antennas on aircraft can be used successfully for both bands. A VHF air band dipole will perform perfectly adequately on UHF and is simple and cheap.
Jason

 

[prcguy]

I can't think if any example of this where a purpose designed VHF airband only antenna has been used on UHF air band. There are dual band antennas made with a separate connector for each band but they were purpose designed to cover both bands. As a general statement a 1/4 wave antenna common to aircraft use will not work at all on its second harmonic due to the very high feedpoint impedance over 2,000 ohms of a the 1/4 wave VHF antenna being used as a 1/2 wave at UHF.

The other problem is band width with the VHF air band covering about 19MHz and when you double that to UHF your at 38MHz band width but the UHF air band is 175MHz wide, so even if you could get a 1/4 wave VHF air band antenna to match in the UHF air band, it could never cover the entire band.

In general an antenna tuned for VHF air band will work pretty well on UHF air band as they are harmonically related (second harmonic); this is deliberate so single antennas on aircraft can be used successfully for both bands. A VHF air band dipole will perform perfectly adequately on UHF and is simple and cheap.
Jason

 

[eorange]

These are the ones with about 30in radials on the skirt and preferably no whip on top.

Does the top whip affect mil air performance? I've never taken mine off; no particular reason. Should I?

 

[prcguy]

The top whip on a RS or Diamond or similar will affect performance but I don't know exactly where or how much. The whips are typically base loaded and tuned sharply around 50MHz which will look like an RF choke at some higher frequencies isolating the whip from the disc. At other frequencies RF will flow through the base coil and whip which would then be in parallel with the top hat and you will have radiation in the Discone mode and radiation in a ground plane mode and they can interact or possibly cancel each other to some extent.

Does the top whip affect mil air performance? I've never taken mine off; no particular reason. Should I?

 

[iMONITOR]

Consider an SIRIO SD 2000 N 100 MHz - 2 GHz Discone

• Base station antenna, omnidirectional unity-gain extremely wide-band suitable for scanner use TX
• Type: disc one frequency range: RX band: 100-2000 MHz
• TX band (@ SWR <= 2): 130-160, 215-440, 610-685, 870-960, 1070-1500, 1620-1800, 1860-2000 MHz imp
• Gain: 0 dBd - 2.15 dBi, maximum power (CW) @ 30°c: 200 watts connector: SD 2000 n: n-female
• Made in Italy

SIRIO SD 2000 @ Amazon $100.00

https://www.amazon.com/Sirio-Antenna-SD2000N-MHz-2-Discone/dp/B008899J8Y

 

[Saint]

Consider an SIRIO SD 2000 N 100 MHz - 2 GHz Discone

• Base station antenna, omnidirectional unity-gain extremely wide-band suitable for scanner use TX
• Type: disc one frequency range: RX band: 100-2000 MHz
• TX band (@ SWR <= 2): 130-160, 215-440, 610-685, 870-960, 1070-1500, 1620-1800, 1860-2000 MHz imp
• Gain: 0 dBd - 2.15 dBi, maximum power (CW) @ 30°c: 200 watts connector: SD 2000 n: n-female
• Made in Italy

SIRIO SD 2000 @ Amazon $100.00

https://www.amazon.com/Sirio-Antenna-SD2000N-MHz-2-Discone/dp/B008899J8Y

Thank you but I already have a discone antenna

 

[Saint]

Consider an SIRIO SD 2000 N 100 MHz - 2 GHz Discone

• Base station antenna, omnidirectional unity-gain extremely wide-band suitable for scanner use TX
• Type: disc one frequency range: RX band: 100-2000 MHz
• TX band (@ SWR <= 2): 130-160, 215-440, 610-685, 870-960, 1070-1500, 1620-1800, 1860-2000 MHz imp
• Gain: 0 dBd - 2.15 dBi, maximum power (CW) @ 30°c: 200 watts connector: SD 2000 n: n-female
• Made in Italy

SIRIO SD 2000 @ Amazon $100.00

https://www.amazon.com/Sirio-Antenna-SD2000N-MHz-2-Discone/dp/B008899J8Y

Thank you but I already have a Discone antenna

 

[flatfoot2421]

Saint, have you considered or looked for a military surplus AT-197A/GR Mil Air discone? They are built like tanks. I understand they show up at amature radio swapmeets for reasonable prices. They do, however, use the harder to locate "HN" connector instead of the more common "N".
I have the "AT" for Mil Air and a old Kraco VHF Discone for civil air and local public safety.

 

[flatfoot2421]

Welp, posted before seeing that you apparently don't want another discone. The DPD Omni is a great option.

Good luck on your quest.

 

[Saint]

Welp, posted before seeing that you apparently don't want another discone. The DPD Omni is a great option.

Good luck on your quest.

sorry about the double post I was on my cell phone when I sent it.
OK thanks for the info, I have been thinking if there is anything out there better then a discone antenna I might try a dedicated antenna for Military air band if it's worth it, the discone works but if there is something better that will give me better reception I would try it, I see some of the antenna's are for UHF and VHF aircraft bands, that would be great if they work better then the discone, I have been doing searches on the internet and came across the MilTenna Omni UHF/VHF Military Bands Base Antenna | DPD Productions antenna but don't no any one whos has used it and could tell me if it's worth the money it would cost me after the exchange rate and shipping so I will keep looking but I just might buy the Miltenna in the end. it would be nice for both UHF and VHF air I think.
Steve

 

[iMONITOR]

Thank you but I already have a discone antenna

I realize that but this is more compact and tuned to the Mil-Air band that you want to use it for.

The MilTenna Omni is also an excellent choice if you want to get away from a discone.

Have you considered a band pass filter for Mil-Air?

The FLT225 is a High-Pass filter designed primarily for radio monitoring of the military band (225 MHz to 400 MHz). This filter effectively attenuates signals below about 225 MHz, such as Paging (152/158 MHz), FM Radio and other strong business band radios.

Receive Filters

 

[ATCTech]

Steve, TACO is in Brantford. They normally don't do retail sales but it doesn't hurt to try. This is the single element/connector version.

UHF Air Traffic Control MULDIPOL™ Omni Military Antenna: TACO Antenna

tacoantenna.com

 

[xms3200]

Highly recommend Taco

 

[prcguy]

Antenna Products has some very similar models to Taco and I believe they will sell to anyone.

https://antennaproducts.com/wp-content/uploads/2020/06/DPV-Series-SpecSheet-1.pdf

 

[Saint]

I realize that but this is more compact and tuned to the Mil-Air band that you want to use it for.

The MilTenna Omni is also an excellent choice if you want to get away from a discone.

Have you considered a band pass filter for Mil-Air?

The FLT225 is a High-Pass filter designed primarily for radio monitoring of the military band (225 MHz to 400 MHz). This filter effectively attenuates signals below about 225 MHz, such as Paging (152/158 MHz), FM Radio and other strong business band radios.

View attachment 106636

Receive Filters

Thanks iMONITOR for the information I was not aware it was tuned to the Mil-Air Band Also, I will check out the filter for the 225-400 band, I also have a FM Filter I used when I had my SDS100 scanner because of the interference in the 108-136 Air band and it did work.
Steve

 

[Saint]

Steve, TACO is in Brantford. They normally don't do retail sales but it doesn't hurt to try. This is the single element/connector version.

UHF Air Traffic Control MULDIPOL™ Omni Military Antenna: TACO Antenna

tacoantenna.com

Thanks ATCTech I sent TACO a email to see if they had any antenna's I could use for the 225-380 and the 108-136 MHz bands
Also thank to everyone for all the information you have provided, it's very helpful to me.
Steve

 

[ATCTech]

Ok, I didn't look at all their product but being a commercial antenna company I very much doubt they'll have VHF and UHF fed to a single connector. They do/did have V/U in the same "tube" but with two outputs. We used that combination at some of our smaller sites and we *never* combined both bands into a single feedline.

 

[Saint]

Ok, I didn't look at all their product but being a commercial antenna company I very much doubt they'll have VHF and UHF fed to a single connector. They do/did have V/U in the same "tube" but with two outputs. We used that combination at some of our smaller sites and we *never* combined both bands into a single feedline.

Yes I will be surprised if they have anything for what I'm looking for in a good price range but it will be interesting what they say in replying to my email, I really think I will buy MilTenna in the end.
Steve