LowBand station antenna options

[DisasterGuy]

Looking for some advice on available station antenna options for lowband. I need one on 39MHz and one on 44MHz. I was hoping to use DB201's but it looks like they are no longer available except for UHF. The only real options I am seeing is the Telewave ANT42D Dipole. I would really rather be into an omni rather than a dipole if possible, particularly since for the pattern I would desire I would need to phase at least two together for each channel and that's both a lot of vertical real-estate and money for what I'm working on.

 

[mmckenna]

I'm a big fan of the Telewave dipoles, but I've only used them on VHF and UHF.

My drive to work takes me past our local CHP office, and they are running a dipole off the side of their tower.

 

[DisasterGuy]

Agree that they are nice, my application is tank top on a water tank and to use them I would need two elements per channel for good North/South coverage. Between the height required and stand-off distance, from a structural engineering perspective on the mount to TIA-222 it would just be a nightmare.

 

[prcguy]

Get one of these surplus military bicone antenna hubs, drill out the element holes to 3/8" then stick in six lengths of 3/8" aluminum tubing. Ive done this and also drilled set screw holes for each element. This makes a 30-90MHz bicone antenna that works great with a good match across the entire range.

The last time I did this I used 10ft elements and the antenna worked really well down to CB giving me a good useable antenna from CB past 6m and everything in between.

BTW this hub auction is a little much, they often show up in the $35 range.

OE-254/GRC Feed Cone Head Antenna, Scuffs/Scrapes, for Military or Ham Radio | eBay

 

[prcguy]

Another great option is the currently deployed COM201B antenna which also covers 30-90MHz and this one is new and complete. I currently have one of these on my roof for VHF lo scanning and occasional 6m use.

Military Antenna System COM201B RAMI201B | eBay

 

[d119]

Kreco Antennas - Catalog

Get your wallet out.

 

[ramal121]

If you are low budget then Sirio has low band offerings.

 

[mancow]

Another great option is the currently deployed COM201B antenna which also covers 30-90MHz and this one is new and complete. I currently have one of these on my roof for VHF lo scanning and occasional 6m use.

Military Antenna System COM201B RAMI201B | eBay

I ended up using L brackets with 8ft CB whips on my COM201B instead of the legs. I then removed a small amount of paint and clamped about a 3 foot section of whip to the vertical element. That thing really came alive with good band coverage.

 

[mancow]

Get one of these surplus military bicone antenna hubs, drill out the element holes to 3/8" then stick in six lengths of 3/8" aluminum tubing. Ive done this and also drilled set screw holes for each element. This makes a 30-90MHz bicone antenna that works great with a good match across the entire range.

The last time I did this I used 10ft elements and the antenna worked really well down to CB giving me a good useable antenna from CB past 6m and everything in between.

BTW this hub auction is a little much, they often show up in the $35 range.

OE-254/GRC Feed Cone Head Antenna, Scuffs/Scrapes, for Military or Ham Radio | eBay

I opened one of those biconical hubs to see what's in it. It's some sort of toroid balun. I wouldn't mind copying it and printing custom hubs from UV resistant ASA.

 

[prcguy]

I ended up using L brackets with 8ft CB whips on my COM201B instead of the legs. I then removed a small amount of paint and clamped about a 3 foot section of whip to the vertical element. That thing really came alive with good band coverage.

I replaced the legs on my outdoor unit with 1/2" EMT of the same length, works great. The stock legs are well made but not suitable for permanent outdoor use.

 

[prcguy]

I opened one of those biconical hubs to see what's in it. It's some sort of toroid balun. I wouldn't mind copying it and printing custom hubs from UV resistant ASA.

Its around a 4:1 balun, I measured one years ago.

 

[RFI-EMI-GUY]

Get one of these surplus military bicone antenna hubs, drill out the element holes to 3/8" then stick in six lengths of 3/8" aluminum tubing. Ive done this and also drilled set screw holes for each element. This makes a 30-90MHz bicone antenna that works great with a good match across the entire range.

The last time I did this I used 10ft elements and the antenna worked really well down to CB giving me a good useable antenna from CB past 6m and everything in between.

BTW this hub auction is a little much, they often show up in the $35 range.

OE-254/GRC Feed Cone Head Antenna, Scuffs/Scrapes, for Military or Ham Radio | eBay

This is a coincidence. I was discussing vertical, wire, fan dipoles 10M to 6M and a 43.04 MHz channel between and it was suggested to make a bi-conical. I am unable to find a calculator to design one, and though maybe a discone calculator would work. What is the characteristic impedance of these antennas?

 

[prcguy]

This is a coincidence. I was discussing vertical, wire, fan dipoles 10M to 6M and a 43.04 MHz channel between and it was suggested to make a bi-conical. I am unable to find a calculator to design one, and though maybe a discone calculator would work. What is the characteristic impedance of these antennas?

I think it depends on how much BW your trying to design for. The military OE-254 covers roughly 30 to 90MHz with about 8ft elements (16ft total height), or close to 1/2 wave long at the lowest freq and about 1 1/2 wavelength at the highest frequency. They angle of the elements would be chosen to tame lobes and keep them near the horizon. The OE-254 has a 4:1 balun and I remember around 25pf capacitor across the 50 ohm side of the balun to help with matching.

There are bicones that cover a much wider frequency range where the element angles are much different to keep lobes under control and the elements can be several wavelengths at the highest frequency. That flavor bicone might need a different matching scheme. I also have a Harris bicone that covers 90-450MHz and it has what looks like a series LC circuit in the hub for matching.

Somewhere I have an analysis and comparison of the OE-254 and the COM-201B by two military contractor guys and they suggested a field expedient version being a bow tie made of wire and sticks with a 4:1 balun with 25pf cap across the 50 ohm side. I'll see if I can locate that.

 

[prcguy]

There is also the Discone to consider and they have been used with great success in the military although other designs are more popular due to the amount of components needed to assemble a Discone in the field. I have two military VHF lo band Discones here, both big and beautiful. Both fold up for transport with one being larger diameter tubing with spring loaded stainless steel cable inside the elements after they are snapped together and the other is a much lighter backpack version made in So Africa and has bungee cord inside the elements to hold them together.

I would probably part with the heavier duty version as its only been on the air once in the last 20yrs during a desert camping trip.

 

[RFI-EMI-GUY]

I am going to have to sketch this out as to whether I have room for a bi-conical vs perhaps a three band element vertical wire fan dipole. It will be hanging from a tree if a wire solution. There is another great spot way in the back, but it would freak out that neighbor, especially if I blow out the TV on her lanaii.

 

[W8UU]

If you're looking for a proven commercial grade performer at a relatively low price, check out the Cushcraft ARX series. I've used the ARX6 for 6 meter ham operation with outstanding results. You can get models that cover different segments of VHF low band from 28 MHz to 54 MHz. DC grounded, easy to assemble, durable but relatively light weight, and around $150-175 USD.

 

[W8UU]

I was hoping to use DB201's but it looks like they are no longer available except for UHF.

You'd think Commscope could build low band models on special order, or maybe have a few in storage to ship out. There are still a bunch of low band users out there who need a quality base station antenna.

 

[prcguy]

If you're looking for a proven commercial grade performer at a relatively low price, check out the Cushcraft ARX series. I've used the ARX6 for 6 meter ham operation with outstanding results. You can get models that cover different segments of VHF low band from 28 MHz to 54 MHz. DC grounded, easy to assemble, durable but relatively light weight, and around $150-175 USD.

But narrow band, maybe 1MHz with reasonable VSWR on the Ringo series. The OP is looking for 5MHz BW and another is looking for 10m through 6m which is about 26MHz BW.

 

[W8UU]

But narrow band, maybe 1MHz with reasonable VSWR on the Ringo series. The OP is looking for 5MHz BW and another is looking for 10m through 6m which is about 26MHz BW.

My understanding was that he wanted an antenna for 39 MHz and another for 44 MHz.
It's hard to broadband a low band antenna.

 

[prcguy]

My understanding was that he wanted an antenna for 39 MHz and another for 44 MHz.
It's hard to broadband a low band antenna.

Hard to broadband a ground plane or Ringo but not bicone or some of the other military designs.