I actually measured the pattern of my TH7 and its replacement, a JK 
Mid-Tri, under exactly the same conditions. The TH7 pattern actually 
looked a bit better, with better f/b. I can't compare forward gain, of 
course.
73,
Scott K9MA
On 9/12/2019 15:41, David Gilbert wrote:
 
You know that power loss doesn't equate to lost pattern gain, right?
 Trapped tribanders have shorter elements, which has an effect on 
pattern, and they have non-optimal element spacing for any particular 
band, which again affects pattern gain.
 I'm not saying that trapped tribanders don't have utility, but 
compared to a modern non-trapped design they suffer from more than 
just the heat they generate.
Dave   AB7E
On 9/12/2019 12:55 PM, Glenn Pritchard wrote:
 
Trapped yagis don't suck up gain, another myth easily dis-proven. I have
 used trapped yagis and mono banders over the course of 30+ years and 
at one
time had the big Wilson 40M3 I believe it was called, 3 full sized 40 
meter
elements on a 40' boom..
It is shown that maybe a trapped yagi has at worst a 0.6 dB loss over a
full sized yagi of the same band. It's no surprise that I like trapped
 yagis because of space restrictions right now and having the ability 
to add
40 meters to one is skookum.
 I would like to have mono banders only for 40 and 20 again, perhaps 
one day.
Glenn, VA7UO
 
 
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Scott  K9MA
k9ma@sdellington.us
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