NMO34b for Lowband 40-45mhz

[skatertj]

I want to get a low band antenna but i dont want to put a 49" whip on my car... I noticed larsen has an antenna, the nmo34, that can be cut to around 36 inchs and receive 40mhz. Im looking to scan 40 to 45mhz on vhf-lo. Would this work at that length or would it not be worth it? This is receive only. Any other antennas I can look at that isnt so long? I know the austin is one but I cant think about spending that much on an antenna just yet.

[Rt169Radio]

Well as far as I know, all lowband antennas are tall so they can receive lowband. I doubt your going to find anything that is short for lowband, even if you did it would probably not work good due to it being short.

[skatertj]

Ya I know they need to be tall, just dont want over 40"... Was just curious if this antenna would be ok to use if it was tuned to 40 mhz and still receive 40-45 mhz

[LtDoc]

If all you would be doing is listening then almost any 'size' antenna will 'work'. If it isn't at least close to the 'right' length you can expect to not listen to very much unless it's a strong signal. There are several ways of electrically 'extending' a short antenna. The 'catch' to that is that the abilities of that 'short' antenna are also going to be 'shortened' when compared to a 'full sized' antenna. If that 'shortened ability' suits your needs then good. I don't know any -sure- way of determining that suitability except by trying it to see if it 'works' or not.
One alternative (not necessarily a good one) is to just mount that too-long antenna some place lower.
- 'Doc

[skatertj]

Ok well what im trying to listen to is Oklahoma Highway Patrol. I believe they use 45.220 in my area. I would like to listen to officers within 5-10 miles, if not alittle further but i really dont want a huge whip on my car. I just happened to see that the NMO34 could be cut to around 36" for 40mhz and thought it might be able to pick up 45mhz just as well.

[W2NJS]

A quarter wave vertical antenna for 40 mHz, if full-sized, would be 70 inches long. If you need a resonant antenna for 40 mHz then the "missing" 30 inches would have to be made up by a coil in the base of the unit. This is how the manufacturers make shorter antennas, so you have to look at the chart for the antenna being offered to see its resonant points vs. various lengths.

[skatertj]

Well i know the nmo34 antenna can be cut to alittle over 36 inchs and resonate at 40mhz. Im only trying to receive up to about 46mhz and below.

[Rt169Radio]

Originally Posted by skatertj

Well i know the nmo34 antenna can be cut to alittle over 36 inchs and resonate at 40mhz. Im only trying to receive up to about 46mhz and below.

Maybe you could try a CB antenna? They are in the lowband area.

[prcguy]

A Larsen NMO low band antenna works very well with in their design range and a version designed for a lower freq but cut short for a higher freq can also work if the whip is not too short. I've used a 40MHz version cut to 6M where the whip was a little less than 36" and it worked ok.

These antennas are somewhat narrow band but if you cut it for a frequency between your needed 40 and 46Mhz range it will probably work better than most scanner antennas there.
prcguy

[skatertj]

Ok well the NMO34 only shows frequency ranges of 34 to 40 mhz. 40mhz being cut at 35 3/16 inchs(shortest chart shows). I wouldnt mind that height on my car if that length could still pick up frequencies around 45mhz.

[Rt169Radio]

Originally Posted by skatertj

Ok well the NMO34 only shows frequency ranges of 34 to 40 mhz. 40mhz being cut at 35 3/16 inchs(shortest chart shows). I wouldnt mind that height on my car if that length could still pick up frequencies around 45mhz.

It would probably still be able to work for 45 MHz since the antenna is in the lowband region, 30 to 50 MHz is lowband VHF.

[dmg1969]

Deleted - wrong thread.