Date: Wed, 11 Aug 2010 17:02:33 -0700
From: "Bill, W6WRT" <dezrat1242@yahoo.com>
Subject: Re: [Amps] Fw: Needed, quality watt meter
>
>The BEST display for adjusting stuff is the kind of
>display (meter) with a moving pointer. Right behind
>that is the bargraph.
REPLY:
There are two different kinds of bargraphs. One just lights the
segments one at a time, full on. The other (better) fades in the next
segment as the measurement increases. That type is as good as a
pointer, IMO. Alpha uses that type on the model 89 I had and probably
others.
73, Bill W6WRT
## agreed. And I forgot to mention that on my description of the Array
solutions
watt meters. The AS bar graph does exactly this. Each segment slowly
lights up, from zero
to fully illuminated . Then the next segment starts up. I think there at
least 80 segments on the
AS display..so tuning an amp is a snap. Heck, you can even tune up..while
talking ! Once tuned for max
using the bargraph... If I switch to the numerical display... I'm very lucky if
I can get all of 1-2 watts more out of the
amp.
## OK. I did notice one anomaly. Once I got up to 700+ watt dead cxr.... I
would notice that
the last 2 x segments on the bargraph were...'dithering' . It was worse with
max power [1290 w cxr]
## Then I put the RF scope on... and could see what the 'problem' was at a
glance. I had 3% ripple
in the stock L4B B+ supply [when sucking 800 ma]. The 3% ripple also
shows up as 'dithering' on the
last 2 x segments of the AS bargraph. The AS wattmeter coupler /display unit
is so fast..it will show ripple
in any B+ supply very easily ! I temp paralleled a 50 uf oil cap with
the stock 25 uf set up...and tripled the C.
Ripple dropped down to 1%. Later, I increased the filter C to a whopping
287 uf..and ripple is now down to
just .26%
## I have since taken the bird pep, and CD pep meter's offline. Other than
2m, I have no use for them. Both the
3 kw and 10 kw AS coupler's will cover 160-6m. They give you a separate
set of calibration pointS [ FWD + RVS]
to program in..when using 50-54 mhz. The bargraph is superb..and so is the
hi/lo pwr alarms..+ the high swr alarm.
You can see all 4 x displays on my qrz page.
later... Jim VE7RF
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