This is good Bill and should be on Ten-Tec's webpage and plastered in our
shacks as we talk about the test (s) results for the next decade.
AND then we should keep in mind 'apples and oranges'. The ramifications of
it all goes to happiness/unhappiness, sales/lack of sales, unbelievable
threads, mis-understandings, hurt feelings, start-up companies, loss of
sleep and appetite, and perhaps other good things. This radio business is
serious don't ya know.
73, Lynn W4NL
----- Original Message -----
From: "Bill Tippett" <btippett@alum.mit.edu>
To: <tentec@contesting.com>
Sent: Friday, July 28, 2006 4:38 PM
Subject: [TenTec] RSGB and ARRL Orion II reviews
> FYI, ARRL used the optional Ten-Tec #2001
> 600 Hz filter for their tests per their normal policy of ordering
> any optional filters closest to their 500 Hz measurement
> bandwidth. Recall that ARRL did not use the TT #217 500 Hz
> for the original Orion tests due to IMD problems. Eventually
> this discovery led to the development of the Inrad #762 600 Hz,
> which in turn led to the 4-pole filters / front end scheme used in
> Orion II. Orion with an Inrad #762 is electrically quite similar to
> Orion II with the TT #2001.
>
> RSGB never orders optional filters for their
> tests, so the stock 1000 Hz roofing filter was used in
> both Orion and Orion II tests. However they apparently
> had a bad 1000 Hz filter in their original Orion test since
> close-in IMD results using the 2400 Hz filter were better.
> The 2400 Hz results were the ones RSGB used in the
> review summary. This time around the 1000 Hz filter had
> better results for 1 kHz IMD spacing as expected.
>
> Bottom line points to remember when comparing
> these product reviews:
>
> 1. ARRL used the stock 1000 Hz for Orion.
> 2. ARRL used the optional 600 Hz filter for Orion II.
> 3. RSGB used the stock 2400 Hz filter for Orion.
> 4. RSGB used the stock 1000 Hz for Orion II.
> 5. Orion/762 should have equivalent IMD/BDR to #2.
> 6. Sherwood used the stock 1000 Hz for Orion.
> 7. Sherwood used the optional 600 Hz (for 2 kHz
> spacing) and 300 Hz (for 1 kHz spacing) for Orion II.
> 8. Sherwood made some anecdotal comments about
> Orion/762 but never published actual measurements.
> 9. The above are not completely consistent but track
> well within a few dB of measurement/sample variation.
> 10. Think mid-90's IMD for Orion/762 and Orion II/2001
> at 2 kHz spacings.
>
> 73, Bill W4ZV
>
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