DBGH Antenna report vs. CM4221

[Kro]

I built a DBGH (ROD version) and install it in the attic. I did not had much time to test it never the less here’s the result.

Since it’s very big I did not install it in the Hot spot of my attic and because of that I also could not oriented it in all direction.

First it is very directional compare to the CM4221 its beam width is probably something like half of the CM4221 beam.

With my CM4221 I already get all the DT channel (From Montreal, Mont-Mansfield, Mont-Lyon) around 100% and it’s still true with the DBGH.

So here the other channel I can get a signal:

                CM4221        DBGH
23   WNPI (DT)__20%__________0%
24   CIVS (A)___Snow_________Clean Picture.
30   CFKS (A)___Snow+________Clean Picture.
39   TFO (A)____Nothing______Sound and a lot of snow.
44   FOX (A)____Grainy_______Clean Picture
48   TVO (A)____Nothing______Sound
49   W49BI (A)__Snow++++_____Snow+++
52   W52CD (A)__BW___________BW

Note:

*WNPI was not really test because I could not turn the antenna toward it, this only proof that the DBGH has a smaller beam.

*57 WCFE (A) is overloading (Bleeding over 56 and 58) with the CM4221 but not with the DBGH.

It seem the DBGH has much more gain than the CM4221 from 14 to ~35, a little more from 35 to ~45, about the same 46 to 53 and less at 57 and over.

Another thing to consider is that I built it! And I’m not really good at this and I build it using whatever peace junk I had in my basement.

Other wise I notice that local analog channels look even better with the DBGH, I was thinking they were perfect but now they are even better. (Most likely because of the smaller beam).

I will eventually move it around in the attic and point it north West and see what I can get (WNPI, WTEN).

[Autofils]

Kro,

Thanks for your DBGH report from St-Eustache in your post (168)

From your description, your reception results seem in agreement with the modeling results.
The model predicts net gain cross-over (DBGH 11Pr collinear rods vs CM-4221) occurs at Ch 52.
From Ch14 -51, the DBGH has higher gain than the CM-4221 .The gains are equal at Ch 52. Above 52, the CM-4221 has increasing gain, which peaks at Ch66.

The modeling predicts a beam-width of around 47 degrees for the CM-4221 and around 38 degrees for the DBGH.

I noticed that besides the CM-4221 antenna at your location, you also list a CM-7778 preamp.
Are your reception report results with or without the preamp?

...thanks

[Kro]

Are your reception report results with or without the preamp?

That is with the Dual-Notch (UT-2700 for uhf 17 and 35) and the pre-Amp.

This morning I notice around 20% signal stength on WNNE (UHF 25) usually with CM-4221 the tuner (LG 5 gen) would have an hesitation (~4 second) but would report 0% that's another indication of higher gain in the 20.

[Autofils]

Originally Posted by Kro

That is with the Dual-Notch (UT-2700 for uhf 17 and 35) and the pre-Amp.

This morning I notice around 20% signal stength on WNNE (UHF 25) usually with CM-4221 the tuner (LG 5 gen) would have an hesitation (~4 second) but would report 0% that's another indication of higher gain in the 20.

Kro,

Thanks for the clarification and the update.

Re the UT-2700
I must admit I had to google the UT-2700 to find out that it is a very interesting Winegard product.
It's an adjustable trap for UHF 470-810 Mhz, with two adjustable filters.
Other readers of this forum may find it useful, so here is some more info...
Kudos to Kro for this gem

UT-2700 ADJUSTABLE UHF TRAP (http://www.winegard.com/offair/traps.htm)
Trap may be tuned over the frequency range of 470 to 810 MHz. Features two separate traps. Both may be tuned to the same frequency to reduce it -15 dB, or separate frequencies to reduce 8.5 dB. Can be mounted indoors or out. Passes VHF frequency; AC/DC passive. (Tunable traps require the use of a scope, analyzer, or signal level meter to tune accurately)"

Here is a review link for the UT-2700...
http://www.epinions.com/content_190042771076