On Thu, 03 May 2001 08:19:05 -0400 Pete Smith <n4zr@contesting.com>
writes:
>
> In some current research on SO2R, I was reminded recently that
> nothing's
> for free. One well-known SO2R op commented that he got only 80
> watts out
> of the bandpass filters that follow his 100-watt class radios, which
> in
> turn means he can not drive his 3-500Z amps to full output.
>
> Is this typical of the bandpass filters available today -- ICE,
> Dunestar,
> Array Solutions? Anything to choose among them in this respect, or
> others?
I did a little experiment this evening with my two Dunestar 600
boxes, a wattmeter, and a dummy load. On each frequency, the filter
box was first put in bypass mode, and the power into the dummy load
was noted. Then the appropriate filter was switched in, and the power
noted again.
Dunestar 600 SN 443
Freq Bypassed Filtered
1830 138Watts 110
3530 140 120 (-.67dB)
7030 140 120
14030 130 112
21030 125 105
28030 120 100 (-.79dB)
Dunestar 600 SN 444
Freq Bypassed Filtered
1830 138Watts 110
3530 130 112
7030 130 112
14030 125 105
21030 120 100
28030 115 95
These losses seem pretty reasonable to me, in terms of dB, but
the meters on the amp don't wiggle as much, and that does have a
psychological impact.
Dave Hachadorian, K6LL
Yuma, AZ
K6LL@juno.com
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