Create Log-Periodic 5130 IN

[tonsoffun]

Have you looked at the KMA log antennas? I accidentally dropped a KMA4113 (41 to 1300MHZ) off the roof and it survived just fine, a Create would have been in lots of pieces. I also have a KMA Rover vertically polarized and am very pleased with it. The KMAs are priced much lower than the Create also.
prcguy

Do you have any info on this company?
Also I just received the VHF LP from Dave and going to build it tomorrow. I still have to put my concrete for the tilt-over mast that I am building(all info in the wiki) then I can give this very well built antenna a review.

 

[prcguy]

Sure, see:
http://www.kmaantennas.com/
I have their 41 to 1300MHz log periodic horizontal and the Rover mounted vertical above it. I made a novel mount to keep the mast at the rear of the vertical log to avoid mast interaction. You can really screw up the pattern with a mast or even coax running next to and parallel with the elements. Here is a pic of the KMAs at the top of my tower, I had to rotate it to fit the format here.
prcguy

Do you have any info on this company?
Also I just received the VHF LP from Dave and going to build it tomorrow. I still have to put my concrete for the tilt-over mast that I am building(all info in the wiki) then I can give this very well built antenna a review.

 

[DPD1]

I've actually been working on a wide band LP.

Just wanted to resurrect this thread and post that the multi band LP is now available. It's 118-1000 MHz... It took a while, but I'm happy with how it turned out. Details are on the Scanner Page of the DPDP site.

Dave
http://www.dpdproductions.com
- Custom Scanner, Aviation, MURS, GMRS, Marine & Ham Antennas -

 

[prcguy]

Dave,
Just curious how you provided the phase reversing short on the back of the antenna? Most companies have a hairpin loop and Create coils this up for some reason. Many commercial and military logs simply extend the feeder booms beyond the lowest freq element, short at the proper spot and use this extension for convenient rear mounting to avoid mast interaction.
prcguy

 

[DPD1]

From everything I've studied about the design, a short is not always necessary, especially in VHF/UHF. To be honest, I've been kind of stumped as to why some do have them, because all the testing I've done indicated it made things worse, not better. Perhaps it might be more of an issue with lower bands. But it works well without one.

A rear mount has always been ruled out, because I wanted people to be able to use a standard 1 1/4" mast. The force involved with supporting the antennas from the rear would mean beefing everything up substantially, which would probably scare off some potential buyers. With an LP, nearby object interaction isn't nearly as bad as something with parasitic elements, like a yagi. I've tested with it completely isolated, and with it mounted, and seen no difference. Not to say that it shouldn't be mounted in an isolated area, but the mast doesn't seem to do anything negative.

Dave
http://www.dpdproductions.com
- Custom Scanner, Aviation, MURS, GMRS, Marine & Ham Antennas -

 

[tonsoffun]

That looks great Dave and by the sounds of it its going to work great as well. I know the LP-VHF beam works amazing for me on my tilt-over, I'm receiving towers that my discone barely got!.
I might have to get the new one now!
Did you discontinue the VHF model?
Take care

 

[DPD1]

Thanks, glad you liked the one you have. You'd probably get a tiny bit more VHF-wise out of that one, just because you have 6 elements all working for you in that area.

The VHF LP may not be gone for good, but it's off the menu for now. The people who purchased it liked them, but there wasn't a huge demand. I attributed that to the fact that it may have been too niche. We can only keep so many things available at one time, so when I decided to do the multi band, something had to go. I'm hoping this one will appeal to people who want more of a do-it-all model and don't want individual antennas for each band. But I will always stick to my advice that, that's the best way to go for best performance.

btw... I don't think I commented, but I liked your tower... Turned out nice.

Dave
http://www.dpdproductions.com
- Custom Scanner, Aviation, MURS, GMRS, Marine & Ham Antennas -

 

[mtindor]

Dave,

Do you have any way to get some audio comparisons on 800 mhz trunked? I'm not nearly as interested in monitoring a local system as I am DXing as many systems I can as far out as possible. I like having 'access' to as many as possible and then listen to them randomly to see if I can find out new info about them. Currently my only comparison would be the telescopic antenna that comes with the scanner. It sounds as though with the log I should be able to receive all of the relatively local 800 trunked regardless where the antenna is pointed (as opposed to with a Yagi where the F/B is so high).

I'd be able to put an LP of that size up 30 feet, no more. Just would like to get an idea if I'm going to see _significantly_ better performance out of an LP up 30 (and associated connector and coaxial loss for 50 feet of coax) compared to just what I recieve now from the telescopic antenna. Past experience in general tells me I should see a huge improvement, but 800 mhz is a different beast.

Mike