Bill,
Thanks for the numbers. I am using the Elecraft XG-1 which can provide a
constant 50 uV or 1 uV signal, crystal controlled at 7.040 MHz. It's been a
real handy addition to my tool kit. They're not that expensive (about $40).
I'm not seeing a 6dB difference between the 1000 and 500 Hz filters when
feeding in a 50 uV signal. With the Orion pre-amp on, the 1000 Hz filter the
Orion S-Meter read 10 dB over s9 and the 500 Hz filter read 12 dB over s9.
The 250 Hz filter read just under s8.
73,
Mark
----- Original Message -----
From: "Bill Tippett" <btippett@alum.mit.edu>
To: <tentec@contesting.com>
Sent: Monday, July 26, 2004 7:11 AM
Subject: [TenTec] Orion Roofing Filter Check
> I also had a problem with high insertion loss
> in a TT217 250 Hz filter. Mine turned out to have 8 dB
> more insertion loss than normal.
>
> If you have a steady signal source, and
> properly working filters, here are the "approximate"
> readings you should see. Remember to set DSP =
> 2000 and do not change it during these checks.
>
> 1000 Hz = S9 (reference should be set in this area)
> 500 Hz = ~S9+6 dB (check with 6 dB ATTN in Orion)
> 250 Hz = S9
>
> As discussed before, the 500/250 Hz filters have
> an additional 12 dB amplifier to compensate for
> their increased insertion loss. The 500 Hz filter
> has ~6 dB insertion loss, therefore it will appear to
> have 6 dB gain. If the 250 Hz is working properly, it
> will have ~12 dB insertion loss which is exactly
> compensated for by the 12 dB amplifier. My first
> TT217 had 19.5 dB insertion loss and the good one
> had 11.5 dB loss.
>
> 73, Bill W4ZV
>
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