Question: Thoughts on antenna suggestion for use at bottom of a hill? Lots of trees.

#21
Rick Antennacraft, and Winegard state antenna gain in dbd.
DON'T COUNT ON IT! Read it, and weep: http://www.winegard.com/kbase/upload/HD-1080.pdf

OK, I admit I looked at half a dozen Winegard spec sheets, and that's the only exception to dBd numbers I could find. :becky:

Also read your AntennaCraft link, and many of the papers cited there. Still no clue why you think their figures are minimums. I think they're averages. I suspect they're maximums! The minimum idea is the last thing that would occur to me -- unless they put it in black and white. :alien:

Rick
 
#22
This is strange, I ran your chart at 50' and got all "LOS', but didn't save the link...sorry.
Don't feel bad -- I got the same thing. But naturally I don't have his exact address. He must live in the bottom of a gulley, or maybe underneath some highway overpass(es). You think overpasses would be in the FCC database?

R.
 
#23
Winegard started using dBi numbers on charts about five years ago for newly introduced products. Old data sheets were not changed.

Channel Master's older data sheets simply uses the ambiguous term of "dB" with no clarification. Usually specified as "average". Newer antennas, like the Masterpiece series, explicitly use dBi but no min/max/avg description.

Antennacraft's data sheets simply have a single gain number for a whole band without clarifying if it's min/max/avg. The footnote does clarify that it is in "dBd".
 
#24
Well, somebody on another board contacted Channel Master directly to confirm the numbers in the chart below were all in dBd.

ChannelMasterChart.jpg

So that's just a few years ago -- after the "HD" models came out. Note the 4 bay 4221HD averages to almost exactly the same gain as the 8 bay 4228HD (11.28 vs. 11.88 dBd) on the 5 UHF stations in current use. Only reason to get a 4228HD is the VHF.

[edit: Correction: On the 5 UHF stations on the chart still in use, 4221HD averages to 11.22 dBd and 4228HD averages to 11.3 dBd -- a virtual dead heat. I added up the wrong column before -- the 4228 column. And I had to blow up the .jpg on my computer to see a .8 change to a .6

That leads to the observation that the 4228HD has lower average gain than the 4228 for current UHF freqs. Reason for that, per the other board, is the balun is mismatched. They no longer have a balun tailored to size on the 4228HD. They just use a standard 300 to 75 ohm transformer.]

What's really hilarious is that CM now claims a range "up to 65 miles" for the CM-4221HD, where just a few months ago 45 miles was the highest figure on that one. Couldn't have anything to do with the DB4e advertising a 65+ mile range, could it??? :huh:

I'll go to 60 miles for either antenna -- not another foot.

RIck
 
Last edited:

Similar threads

Top