300ohm,

Thank you very much for the CM-3021 modification instructions to dramatically increase your vhf-hi gain and help a bit on uhf gain as well.
longer bottom ubolt
plastic or durable wood spacer
36" wide by 30" high of 2" X 4" mesh

Sounds straight forward and simple. However, 4.1 (UHF 48) is the least reliable during a storm.

Norway Spruce last more than 100 years, so our neighbor probably won't have to worry about removal costs.
Norway Spruce windbreak: Our neighbors could not have chosen a more perfect DTV OTA "counter-technology."

36" wide by 30" high of 2" X 4" mesh
If the CM-3021 is the same as the CM-4221a (which I read it was) make that 36" by 36". That will help UHF even more. (the existing reflector should be 36 inches high) Just attach the 2" X 4" mesh to the existing reflector, so the reflector center will remain 1" X 2" mesh.

OK: 36" wide by 36" high of 2" X 4" mesh

Better UHF performance is what's needed most.

Is there more than one quality of 2" X 4" mesh (galvinized?) - that will stand up to the elements longer?

Thank you!

However, 4.1 (UHF 48) is the least reliable during a storm.

With the wider reflector mod, you should be able to pick up NBC from Baltimore rf 11, and from Lancaster rf 8. One of those should be clear during a storm, heh.

(the existing reflector should be 36 inches high) Just attach the 2" X 4" mesh to the existing reflector, so the reflector center will remain 1" X 2" mesh.
The original reflector is 36" high x 20" wide.

1.) Is there more than one quality of 2" X 4" mesh (galvinized?) - that will stand up to the elements longer?

2.) Is there a recommended attachment method for the 36" x 36" mesh to the existing reflector? Zip ties?

With the wider reflector mod, you should be able to pick up NBC from Baltimore rf 11, and from Lancaster rf 8. One of those should be clear during a storm, heh.
Sounds good.

Thanks!

1.) Is there more than one quality of 2" X 4" mesh (galvinized?) - that will stand up to the elements longer?
Yes, there are many different gauges and quality of galvanization or plastic coatings. For reflector gain purposes in this case, the differences between them are going to be very tiny, so even plastic coated is fine.

Is there a recommended attachment method for the 36" x 36" mesh to the existing reflector? Zip ties?
Yes, UV resistant zip ties will work, but its hard to determine their future quality too. To be safe, I would just twist some soft copper or aluminum wire to tie it on to the existing reflector and then clip off the excess ends of the wire to make it neat.

Thanks, will do. Will this mod be sufficient to consistently receive all VHF-hi within 45-miles (DC & Balt) or will we need a BLV6F, ANT3100510, YA-1713 or Y10-7-13?

When I tested the CM-3021 on top of the roof, the VHF performance was non-existent for VHF 7, 8, 9, 11, 13.

However, as an indoor 2nd-floor window antenna, we consistently receive 7 & 9, 11 much of the time, and 13 some of the time.

mechanical wise the 91xg is like a kia vs Ferrari but w/lifetime warranty. so you cant go wrong. the sigma9 hd has 1 db advantage past 700 MHz so it is useless
as per fracarro charts. i am currently using the blu 420f here in Mississauga. the
sigma series of antennas have a massive reflector of all my collection of yagis.

the big plastic driven element of the sigma6 hd are the same as the blu series of antennas.

mechanical wise the 91xg is like a kia vs Ferrari but w/lifetime warranty. so you cant go wrong. the sigma9 hd has 1 db advantage past 700 MHz so it is useless as per fracarro charts. i am currently using the blu 420f here in Mississauga. the sigma series of antennas have a massive reflector of all my collection of yagis.

Gain at ch-14:

I've read many excellent reports on the 91XG. It's the most cost-effective of these choices. 11.8 dBi (~9.65 dBd) @ 470 Hz

The Fracarro sigma 6 & 9HD look appealing due to their respectable gain and smaller size - Less prone to ice &/or wind damage and less conspicuous from the street.
Sigma 9HD provides 14 dBi (~11.85 dBd) @ 480 Hz
Sigma 6HD provides 13 dBi (~10.85 dBd) @ 480 Hz

Which UHF yagi is best able to resolve or minimize multi-path interference? That's our biggest challenge. Thanks

mechanical wise the 91xg is like a kia vs Ferrari but w/lifetime warranty. so you cant go wrong.
It is very kind for AD to provide free parts to it's customers. That definitely builds good will and word-of-mouth advertising.

However, the owner's time & labor is needed to remove the antenna from the mast, replace the broken part and reinstall the antenna on the mast. Hopefully, such repairs aren't need in the middle of winter.

i have the blu 420f, sigma 6 hd and portensigne lambda from france, and i can tell you that they are the Ferrari of the antennas, zinc plated booms (mirror finish) performance is very good with wide bw.

1.) What is the most distant station you consistenly receive with your:

420f?
Sigma 6 hd?


2.) Which of these two Fracarros best handles multi-path interference?

Thanks

83.8 miles nbc 2.1 rf33 2 edge. 49 dvuv on my meter this winter.

the sigma6 hd beats the blu420f in 470 to 600 MHz due to its reflector size. it is huge and heavy short antenna. ( again by fracarro charts they are the same performance)

Very impressive! is that with the 420F or Sigma 6 hd?
Are you using a preamp?
What is your elevation and your height AGL?

edtrutone,

Thanks for your reply.


Which UHF yagi you've used is best at resolving multipath interference?
Are you also familiar with the Sigma 9HD?

correct with Research comm preamp from uk #9254 located in 2nd floor beside the window w/ j mount.

AD 91xg, but i will take the blu 920 8ft long yagi antenna. due to the quality.

mechanical wise the 91xg is like a kia vs Ferrari but w/lifetime warranty. so you cant go wrong. the sigma9 hd has 1 db advantage past 700 MHz so it is useless
as per fracarro charts. i am currently using the blu 420f here in Mississauga. the
sigma series of antennas have a massive reflector of all my collection of yagis.
I would say the 91XG is more like a Corvette than a Kia. In other words, just as fast as a Ferrari, but made in the USA, and a whole helluva lot cheaper.

83.8 miles:
correct with Research comm preamp from uk #9254 located in 2nd floor beside the window w/ j mount.
With which antenna?

blu420f antenna.