Hello, I'm thinking of getting the Grove Scanner Beam Antenna II (http://www.grove-ent.com/BEAMII.html). However, the specs say this antenna has no gain in the 30-50MHz range. Are there any good antennas around the same price range that have any gain in the 30-50MHz range? Is it really that important? Is it even possible? It will probably be the main frequency range I scan, and I'll be scanning areas at least 35 miles away, if not more. I'm just curious. I've read rave reviews about how far this antenna can receive, but I'm not sure if I should look for an antenna with gain on the 30-50MHz range.
Low-band Antenna with gain
- Thread starter Patrick_
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N_Jay
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Gain at lowband take a BIG antenna.
It is also difficult/impossible to design an antenna with gain and wide bandwidth.
It is also difficult/impossible to design an antenna with gain and wide bandwidth.
ka3jjz
Wiki Admin Emeritus
A better question to ask is whether you have any low band activity in your area. If there is very little, and you're not interested in chasing low band skip, then the answer is that it isn't all that important. Try not to buy an antenna just on its specs alone, but what it is you are really trying to hear. 73s Mike
k9rzz
Member
Looking at the element lengths and the short boom, I doubt it has much - if any - gain on low band VHF.
If you really want something directional, something like this would be better I'd think:
http://www.antennasdirect.com/V4_antenna.html
That folded dipole arrangement would give you better frequency bandwidth. If you wanted to build, I'd go at least 8 to 10 feet long, cut the reflector for the lowest frequency and the shortest director for the highest frequency you're interested in. Of course, you'd want to mount it vertically, so use a non-metalic mast.
If you have a particular direction in mind, a longwire might work well.
I've never really tested my 6 meter antenna on VHF low ... a 10 meter beam might work as well.
John K9RZZ
zz0468 said:
Are you talking about the Grove Scanner Beam II, or the other suggested antenna? If you're talking about the Grove, it probably is just a TV antenna, but it's rated for a broader range of frequencies.
The main frequencies I want to monitor will be low-band (30-50MHz) at long range... at least 35 miles, and I may be moving soon to an area over 75 miles away (as the crow flies). I'd also like to pick up some other bands, as well, however.
That antenna you suggested to me has a quoted range of "up to 25 miles", which wouldn't be enough for me.
Do you really recommend I build my own? Would it be cheaper? I'm afraid I wouldn't be able to tune it well, so I'd really rather purchase a known antenna, so I know what I'm getting, it's range, etc.
timmer
Member
If you want strictly low band coverage, I would suggest a cb antenna, possibly the Antron 99. I have a Grove scanner beam, and it does pretty good, actually really good, on vhf high band and uhf, but is only fair on vhf low band, and definitely not directional on low band. I've heard great things about the Antron 99 cb antenna. It's supposed to be very good on vhf low band. It's not extremely expensive and isn't as huge as some of the ham antennas made for this range. It is a single vertical element, with no radials.
doctordave
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Plenty of antennas out there will do OK. I've had good success copying 39 MHZ stations (not the cars) over 75 miles away, just using an elevated "Scantenna" and an old Radio Shack mombo ground plane scanner antenna (both mounted 25' above ground level). I also built a ground plane antenna, cut specifically for 39 MHZ, based on instructions from the ARRL website and had slightly better success w/ range.
If you don't mind spending some money, there are also some great commercial-grade products out there. Tessco has a few as low as the $200 range:
http://www.tessco.com/products/displayProducts.do?groupId=340&subgroupId=17&search=false&page=2
(make sure to scroll through all four pages of the above-listed link)
If you don't mind spending some money, there are also some great commercial-grade products out there. Tessco has a few as low as the $200 range:
http://www.tessco.com/products/displayProducts.do?groupId=340&subgroupId=17&search=false&page=2
(make sure to scroll through all four pages of the above-listed link)
Last edited:
timmer said:
Can you tell me how far away you can pick up signals on low with the Grove, the quality of the signal, and how high up your antenna is?
Since the Scanner Beam is not directional on low, do you think a Scantenna would be better?
My main focus, really, is to get "high-milage" reception.
There is the military OE-254 30-88MHz bicone that shows up surplus in the $75-$100 range that is an excellent VHF low band scanner antenna. It will work much better than using a CB antenna or ground plane cut to a specific frequency. This antenna is about 16ft tall, you don’t get a free lunch on this band.
prcguy
prcguy
ScannerDude244
Member
doctordave said:
damn SG101 Series 35 Lbs!
timmer
Member
I don't want to bombard you with possibilities, but the two omni-directional antennas that come to mind are the scantenna and the Nil-Jon base antenna. The scantenna isn't quite as sturdy in my opinion as the nil-jon. Both are supposed to be excellent in the vhf high band range. The Nil-Jon is small and not as noticeable as the larger scantenna. I'm sure there are better more expensive commercial grade antennas out there if want to go that route. The scantenna can be bought from several places, including antenna warehouse and Grove. The Nil-Jon can be bought from Grove, www.grove-ent.com. It is more expensive at around 95.00.
They occasionally turn up on Ebay and you might check with Steve Haney, a mil surplus dealer friend. You can look him up on Ebay under haneyelect. All you really need is the center hub with a short insulated mast section and you can probably tap the element holes and use 3/8” diameter aluminum rods or tubing for the 6 elements. The original element OD is .335” where it meets the hub and that should work with 3/8-24 or possibly a 3/8-16 thread. Here is another mil surplus dealer that has the hubs but I think the price is a bit high. http://www.american-milspec.com/p1885.html
prcguy
prcguy
Patrick_ said:
How well would a TV antenna, such as this 160", 57 element antenna from RadioShack (http://www.radioshack.com/product/i...upport&x=11&numProdsPerPage=100&tab=techSpecs) work for VHF Hi/Low? It's got a lot of surface area; I'm wondering if it would do better than a Grove Scanner Beam II or Scantenna for long range... the specs say VHF range: 190 miles UHF range: 100 miles FM range: 100 miles. This is what I'm looking for! Of course, there's always the cheaper option: the 80", 32 element TV antenna (http://www.radioshack.com/product/i...s&origkw=antenna&support=support&tab=features) is spec'd for VHF range: 90 miles UHF range: 70 miles FM range: 70 miles. The bigger antenna seems safer for my needs (190 rated for VHF).
I just need to know the VHF frequency ranges for it... I wonder if it covers VHF hi/low band fully? Does anyone recommend I use a TV antenna? Anyone had experience with using it for a scanner? It sure sounds darn good for the money.
I just need to know the VHF frequency ranges for it... I wonder if it covers VHF hi/low band fully? Does anyone recommend I use a TV antenna? Anyone had experience with using it for a scanner? It sure sounds darn good for the money.
kf4pep
Member
If all you are interested in listening to is in one direction, buildone of these:
http://www.iol.ie/~bravo/ahexbeam.htm
Or build a quad:
http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=10840
For an omni, here are plans for a 6m J-pole. Its about as much gain as you will get this low in an omni
http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=7573
http://www.iol.ie/~bravo/ahexbeam.htm
Or build a quad:
http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=10840
For an omni, here are plans for a 6m J-pole. Its about as much gain as you will get this low in an omni
http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=7573
kf4pep
Member
Patrick_ said:How well would a TV antenna, such as this 160", 57 element antenna from RadioShack (http://www.radioshack.com/product/i...upport&x=11&numProdsPerPage=100&tab=techSpecs) work for VHF Hi/Low? It's got a lot of surface area; I'm wondering if it would do better than a Grove Scanner Beam II or Scantenna for long range... the specs say VHF range: 190 miles UHF range: 100 miles FM range: 100 miles. This is what I'm looking for! Of course, there's always the cheaper option: the 80", 32 element TV antenna (http://www.radioshack.com/product/i...s&origkw=antenna&support=support&tab=features) is spec'd for VHF range: 90 miles UHF range: 70 miles FM range: 70 miles. The bigger antenna seems safer for my needs (190 rated for VHF).
I just need to know the VHF frequency ranges for it... I wonder if it covers VHF hi/low band fully? Does anyone recommend I use a TV antenna? Anyone had experience with using it for a scanner? It sure sounds darn good for the money.
Channel 2 starts at 55.25, so anything lower than that you will find this antenna probably not a great performer on.
More bang for your buck would be one of those I lined to above scaled for your freq
Interesting... I looked at the grove antenna, particularly the specs. The longest element is 96", and that corresponds to a half wave at around 61.5 MHz. So, that would tell me that below that frequency, there is zero gain, and it's behaving more or less like a mass of metal connected to a receiver, as opposed to a directional antenna. I note that it's "rated" down to 30 MHz, but the spec doesn't claim any gain until 100 MHz. By the way, the term "zero gain" is not necessarily a bad thing, especially at the lower frequencies.
Another caveat... don't pay any attention to ratings such as "100 mile range" on tv or scanner antennas. TV's are listening to broadcasters running oh, say, 50,000 watts. Your favorite lowband cop channel is doing good if he's running 250 watts. Don't try to compare apples and bananas. There are so many variables involved, that the range figures are completely misleading. All they really tell you is that one antenna is bigger than another.
Another caveat... don't pay any attention to ratings such as "100 mile range" on tv or scanner antennas. TV's are listening to broadcasters running oh, say, 50,000 watts. Your favorite lowband cop channel is doing good if he's running 250 watts. Don't try to compare apples and bananas. There are so many variables involved, that the range figures are completely misleading. All they really tell you is that one antenna is bigger than another.
k9rzz
Member
Are you interested in hearing in one direction or in several?
Either way, if you want a high performance antenna for low band VHF, I think you're going to have to build - either from scratch or modify a CB antenna.
If you're interested in only one direction, I'd try a directional wire antenna if you can.
BUilding isn't really that hard, and if you chose that route, there's plenty of helping hands here to guide you along the way.
Otherwise, it's mast and rotator, $$$ !
John K9RZZ
Either way, if you want a high performance antenna for low band VHF, I think you're going to have to build - either from scratch or modify a CB antenna.
If you're interested in only one direction, I'd try a directional wire antenna if you can.
BUilding isn't really that hard, and if you chose that route, there's plenty of helping hands here to guide you along the way.
Otherwise, it's mast and rotator, $$$ !
John K9RZZ
k9rzz
Member
Here you go:
VHF Yagi Antenna- Model 45-3 - 40-50 MHz
http://www.astronwireless.com/astrondocs/vhf_low_45-3.html
Electrical Specifications
Frequency Range 40-50
Gain, dBd
5 minimum
Front to Back Ratio, dB
20 minimum; 25 typical
VSWR (50 Ohms)
1.2:1 typical
1.5:1 bandwidth
2 minimum; 3.5 typical
3 dB Beamwidth E/H Planes
67/119 degrees
Stacking Distance, E/H Planes 15 (4.6) / 8.5 (2.6)
Maximum Power
1500 watts
Termination, feet (m), coax
UHF Male, 2 (.61), RG303
Polarization
Horizontal
No price listed, but you could inquire.
Probably cheaper to build your own, but if you want to buy, that's what you want.
They will also build you one for the lower end - 30 Mhz.
John K9RZZ
VHF Yagi Antenna- Model 45-3 - 40-50 MHz
http://www.astronwireless.com/astrondocs/vhf_low_45-3.html
Electrical Specifications
Frequency Range 40-50
Gain, dBd
5 minimum
Front to Back Ratio, dB
20 minimum; 25 typical
VSWR (50 Ohms)
1.2:1 typical
1.5:1 bandwidth
2 minimum; 3.5 typical
3 dB Beamwidth E/H Planes
67/119 degrees
Stacking Distance, E/H Planes 15 (4.6) / 8.5 (2.6)
Maximum Power
1500 watts
Termination, feet (m), coax
UHF Male, 2 (.61), RG303
Polarization
Horizontal
No price listed, but you could inquire.
Probably cheaper to build your own, but if you want to buy, that's what you want.
They will also build you one for the lower end - 30 Mhz.
John K9RZZ
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