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FanofOTA66 well sounds like you got into a bit of trouble with your mod, but don't worry it's nut junk yet... you could use a file or some sand paper to file the edge of the rods that you cut so that they'll fit back into the plastic. Oh ya and don't worry about that one rod thats bent you can just bend it back and when you get it into the plastic holder it will all line up. Don't worry be happy :) well let me know if this idea works for ya i think it should it's just a little filing. Bill
 

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Then the 3rd Mesh hack I used metal cutting scissors and I screwed up because the plastic things won't fit anymore and the ends are very sharp and one rod is kinda bent. I measured that I cut 5 inches from 24 to 19 across. But with the sharp metal ends and plastic parts not able to fit, I guess this antenna is not good anymore.
The plastic pieces dont do anything for the antenna except to give it a bit more structural stability. No, you dont have to throw the antenna away.
 

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Flipping the balun vs pulling it out?

Hello.

Installing my 4221HD on my roof tomorrow (to get it higher up) and while I have it down (from previous location) I'm going to do remove the V-clips and to the balun mod. Just wondering, is there any difference, other than visual, between flipping the balun vs pulling it out?

Basically, I have a limited window to get this job done tomorrow and I'd like to do the balun flip tonight while I have the unit down from the previous location. Doing the flip means I gotta go and get so coax seal I assume? If so, is that something I could find at my local big box hardware store? And also, what exactly do I need to apply this sealant to (ie. what am I trying to seal up)?

Both mods (pulling vs flipping) are simple, but one just seems to require the use of the sealant, so wondering if it's worth it vs pulling it out from the base?

FYI — I'm not really worried about "appearance" since nobody is going to be able to see this thing where I'm mounting it.

k.

EDIT: Checked my local hardware store and nothing with regards to "coax sealant" — is there something specific I should be looking for?
 

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EDIT: Checked my local hardware store and nothing with regards to "coax sealant" — is there something specific I should be looking for?
Check your local Rat Shack, they may carry it.

Just wondering, is there any difference, other than visual, between flipping the balun vs pulling it out?
Ive never done the mod, but I wouldnt think so as long as you get the phasing bars the same distance away from the boom.

I would be careful though, some types of aluminum alloys are brittle and will break when bending, so you may want to be prepared to replace the bar.

Some alloys and pure aluminum will bend very nicely. But I have no idea what alloys the CM4221HD uses.

Brittle aluminum alloys can be made to bend by applying a proper amount of high heat, but you risk melting the balun box.
 

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You want to waterproof the leads completely against rust and deterioration, and you want to make sure that no water enters the balun. Try to leave a small weep hole at the bottom of the balun facing downwards so that any condensation inside will have an egress and no rain will flow in.
 

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Well, my assumption was we're not talking about a flip in terms of up/down (with regards to changing the coax connection from coming out the bottom to coming out the top), but rather removing the entire bar the balun is connected to and "flipping it over" so that the "back" of the balun, that used to be facing the boom, is now facing away from the boom (so, looking at it, the parts of the bars that originally angled towards the boom are now opposite so they angle away from the boom)?

Am I incorrect in my thinking?

k.
 

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Flip questions

hey theboyk if you want to just do the flip you don't need to seal up anything. just loosen off the four bolts and flip it around and tighten them back up. Thats it, takes like 2 minutes. hope this clears things up for ya....
 

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CM4221HD Hack for VHF?

Hi folks,

Just a quick question. Is there a hack that can increase the VHF-HI gain for a CM4121HD. Something like Narods?

I am going to build a GH but wondered if anyone had tried this.

Thanks
 

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Adding some 34"-36" rods on or behind the reflector should work. A similar hack for the M4 is discussed beginning at post #837 in this thread.

Note that the CM4228 is better than the CM4221 for VHF-hi and I suspect that an M4 or GH design stacked side-by-side with long reflectors would be good as well.
 

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Has anyone modeled or has an opinion on this VHF mod for the CM4221HD

If I cut the existing reflector rod from the square tubing and added four pieces of 1" or 3/4" flat aluminum bar 36" long bolted to the back of the reflector would it make a big difference on VHF stations?

I do not receive ch 11 from Hamilton and ch 9 from toronto with my current reflector less 4221hd
 

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If I cut the existing reflector rod from the square tubing and added four pieces of 1" or 3/4" flat aluminum bar 36" long bolted to the back of the reflector would it make a big difference on VHF stations?
Yes. 36" would be better for channel 7, while 32" would be better for channel 11.
 

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Do you know how good it would be?
Havent modeled it on the new CM4221HD, but on mclapps models and the old CM4221 and the DB4, 28 to 36 inches is the key for vhf-hi reception, with 28 a bit better for 13 and 36 a bit better for 7. So 34 would be fine for 9.

Would it just be better to just junk the antenna and build a gh4n?
No dont junk it.
 

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This hack worked perfectly! Did all three steps and I'm now pulling in some key Buffalo stations I wanted, and only sacrificed OMNI 2, but I never really watched anything on there anyway. Thanks for the tip/info, much appreciated!
 

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Before this mod I could barely pull in any Buffalo, except for maybe at night just WLNO. Now I've got that, all the WNED stations, Fox 29, The Country channel along with my toronto stations with no rotor required. With my setup and my location I know WGRZ and WIVB are never going to come in for me, but with all the Toronto channels, their simulcasts will pretty much cover what I need.

Again, astonished how this simple mod completely opened up my setup.
 
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