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Author Topic: Trying to decide between W6LVP loop and vertical dipole  (Read 1296 times)

Offline bandarr3000

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Trying to decide between W6LVP loop and vertical dipole
« on: April 15, 2018, 2152 UTC »
I'm trying to decide between a W6LVP loop and a vertical dipole, given that I have neither the space for a horizontal dipole nor radials for a vertical.  Right now I'm just listening on HF and MW, but I'm saving my money for an HF rig and a 20m vertical dipole for TX is possible with my back yard.  Am I going to get much better performance out of the W6LVP vs. a vertical dipole?  I'm in a suburban environment with plenty of noise.  Given my budget, I can't get both.
Yaesu FTDX3000D
SDRPlay RSP1A
W6LVP loop antenna
EFHW 40-10 as inverted L
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eQSL please to bandarr@gmail.com

Online RobRich

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Re: Trying to decide between W6LVP loop and vertical dipole
« Reply #1 on: April 17, 2018, 2249 UTC »
W6LVP loops are receive only.

Are you just interested in the 20m band? Lots of amateur activity is on 40, 80, and even 160 right now due to the current solar cycle.

If you are talking about pirate radio, then you probably should be looking at 40m solutions if going for something off the shelf.

Anyway, there are many verticals available with elevated, loaded radials. Check Cushcraft, MFJ, etc. They can be a compromise on bandwidth and gain, especially on the lower bands due to reduced length and increased element loading, but some antenna is generally better than no antenna. ;)

You might want to look at cobweb, hexbeam, and multi-band yagi antennas as well.
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Offline bandarr3000

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Re: Trying to decide between W6LVP loop and vertical dipole
« Reply #2 on: April 18, 2018, 0307 UTC »
I'm interested in everything from 160 to 10.  160 is a pipe dream with my yard.  My back yard is 110 x 40, with the 110 running east-west.  I could  easily run a 40m dipole E-W, but I'd like to DX Europe and east Asia, and an E-W orientation probably wouldn't be that great.  Unless, of course, propagation follows great-circle paths.   
« Last Edit: April 18, 2018, 0320 UTC by bandarr3000 »
Yaesu FTDX3000D
SDRPlay RSP1A
W6LVP loop antenna
EFHW 40-10 as inverted L
Grand Rapids, MI

eQSL please to bandarr@gmail.com

Offline ChrisSmolinski

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Re: Trying to decide between W6LVP loop and vertical dipole
« Reply #3 on: April 18, 2018, 1157 UTC »
You may want to seriously consider a Crossed Parallel Loop. This antenna will give you all of LW, MW, and HF.

I built one last summer. For the size, it is an excellent performer. It's not quite as good as my sky loop or beverage antennas of course, but still works well, and is my go-to antenna for the higher bands, where they are too long. But it is still a decent performer on the lower bands, I can pick up Europirates and even Lupo Radio from Brazil. It also works well down to MW and even LW.

You'll need to get the LZ1AQ amp, which runs a bit north of $100 with shipping. In my case I used PVC for the frame, wood would work as well. Plus some large gauge wire for the four loops.  You'll need to put the control board in a box (plastic is ok) with some switches to configure the various modes. Connection between the control board and antenna is via shielded ethernet cable, which carries power, control lines, and the return signal. 

My build notes are here: http://www.radiohobbyist.org/blog/?p=2340
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
NRD 545 / netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 670 ft horizontal loop / 500 ft northeast beverage / 58 ft T2FD / 300 ft south beverage / 43m / 20m / 10m  dipoles / Crossed Parallel Loop

Offline bandarr3000

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Re: Trying to decide between W6LVP loop and vertical dipole
« Reply #4 on: April 18, 2018, 1332 UTC »
Chris, this may be exactly what I need for SWL. Also, how do you deal with strong local AM stations?  Do you have notch filters? 
Yaesu FTDX3000D
SDRPlay RSP1A
W6LVP loop antenna
EFHW 40-10 as inverted L
Grand Rapids, MI

eQSL please to bandarr@gmail.com

Offline ChrisSmolinski

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Re: Trying to decide between W6LVP loop and vertical dipole
« Reply #5 on: April 18, 2018, 1345 UTC »
Chris, this may be exactly what I need for SWL. Also, how do you deal with strong local AM stations?  Do you have notch filters?

Fortunately I don't have any issues with strong local AM stations, the closest is a 5 kW on 1280 that is about 10 miles away. It still puts in a decent S9+60 with the sky loop (which is close to 1 wavelength at 1280), but doesn't cause any mischief.  The LZ1AQ page has some tech notes on the amplifier, it seems to tolerate strong local RF fields OK.

You can build a single or double loop first with the LZ1AQ amp to get an idea as to how it performs, before building the crossed parallel loop. This was my first build with the amp: http://www.radiohobbyist.org/blog/?p=2130  Something like that, even with just a single loop, should let you get up and running fairly quickly with a minimal investment of time You can then build the crossed parallel loop while using that antenna, then switch over when it is done, which is what I did.

For someone with limited space, the crossed parallel loop is probably the best route. From those who have compared both, it sounds like it is in the same ballpark as a Wellbrook, for significantly less money.
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
NRD 545 / netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 670 ft horizontal loop / 500 ft northeast beverage / 58 ft T2FD / 300 ft south beverage / 43m / 20m / 10m  dipoles / Crossed Parallel Loop

Offline bandarr3000

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Re: Trying to decide between W6LVP loop and vertical dipole
« Reply #6 on: April 18, 2018, 1349 UTC »
Thank you.  I was looking for a cheaper option, and I'll definitely experiment. One thing I forgot to ask:  You mentioned directionality.  Are the nulls along the axis of the loop or broadside?  Thanks again.
Yaesu FTDX3000D
SDRPlay RSP1A
W6LVP loop antenna
EFHW 40-10 as inverted L
Grand Rapids, MI

eQSL please to bandarr@gmail.com

Offline ChrisSmolinski

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Re: Trying to decide between W6LVP loop and vertical dipole
« Reply #7 on: April 18, 2018, 1647 UTC »
One thing I forgot to ask:  You mentioned directionality.  Are the nulls along the axis of the loop or broadside?  Thanks again.

Good question  ;D  I believe the nulls were like a regular loop, perpendicular to the plane of the loop, but it has been a while since I used it on a rotor. The directionality was never impressive, from memory.
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
NRD 545 / netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 670 ft horizontal loop / 500 ft northeast beverage / 58 ft T2FD / 300 ft south beverage / 43m / 20m / 10m  dipoles / Crossed Parallel Loop

Offline pinto vortando

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Re: Trying to decide between W6LVP loop and vertical dipole
« Reply #8 on: April 19, 2018, 0010 UTC »
110 x 40 sounds like plenty of room for a vertical.
« Last Edit: April 19, 2018, 0022 UTC by pinto vortando »
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Offline bandarr3000

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Re: Trying to decide between W6LVP loop and vertical dipole
« Reply #9 on: April 20, 2018, 1733 UTC »
It would seem like plenty of room but I don't have a spot where I can have radials in all directions. 
Yaesu FTDX3000D
SDRPlay RSP1A
W6LVP loop antenna
EFHW 40-10 as inverted L
Grand Rapids, MI

eQSL please to bandarr@gmail.com

Offline pinto vortando

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Re: Trying to decide between W6LVP loop and vertical dipole
« Reply #10 on: April 20, 2018, 2106 UTC »
It would seem like plenty of room but I don't have a spot where I can have radials in all directions.

Radials in all directions is the ideal, however, if you can at least get some radials in the ground the vertical will work.
Unfortunately, we can't always have the ideal, we have to work with what we have. 
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Offline bandarr3000

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Re: Trying to decide between W6LVP loop and vertical dipole
« Reply #11 on: April 21, 2018, 0035 UTC »
@Chris:  For the LZ1AQ, do you use a linear or switching power supply?
Yaesu FTDX3000D
SDRPlay RSP1A
W6LVP loop antenna
EFHW 40-10 as inverted L
Grand Rapids, MI

eQSL please to bandarr@gmail.com

Offline ChrisSmolinski

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Re: Trying to decide between W6LVP loop and vertical dipole
« Reply #12 on: April 21, 2018, 1126 UTC »
@Chris:  For the LZ1AQ, do you use a linear or switching power supply?

Linear. Always use a linear supply for such things. You need 12 volts out at the amp (it has a 10 volt regulator), so with cable losses you might need a supply with higher voltage. I use a beefy 12V supply that puts out closer to 14V under low loads (the amp draws about 100 mA).

The amp is fed with shielded ethernet cable, not coax. One pair is the return signal, the others are power and control lines. I just had to repair the cable in fact, some critter chewed it.  I have it elevated now where it comes out of the ground (excess cable was laying on the ground) so I hope that prevents a repeat.
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
NRD 545 / netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 670 ft horizontal loop / 500 ft northeast beverage / 58 ft T2FD / 300 ft south beverage / 43m / 20m / 10m  dipoles / Crossed Parallel Loop

Offline bandarr3000

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Yaesu FTDX3000D
SDRPlay RSP1A
W6LVP loop antenna
EFHW 40-10 as inverted L
Grand Rapids, MI

eQSL please to bandarr@gmail.com

Offline ChrisSmolinski

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Re: Trying to decide between W6LVP loop and vertical dipole
« Reply #14 on: April 23, 2018, 1318 UTC »
Thanks, Chris.  Would a cheapie ps like this work?  https://www.amazon.com/dp/B0002JTD2K/?coliid=I1L152JX52YJUO&colid=2H3S5GQMGL5W8&psc=1&ref_=lv_ov_lig_dp_it

Yes, but that is overkill. I am using a 12V wall wart transformer. You may have some laying around the house. You can probably find one at Goodwill for a buck or two. Just make sure it is linear (it should feel heavy from the transformer).
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
NRD 545 / netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 670 ft horizontal loop / 500 ft northeast beverage / 58 ft T2FD / 300 ft south beverage / 43m / 20m / 10m  dipoles / Crossed Parallel Loop