Although the Orion V2 code still has some problems/issues with performance, one
area that appears to have been addressed in the V2.06X releases is the speech
processing performance. Earlier versions of the V2 code suffered from a
combination of audio distortion and weak, if any, compression. The V2.06X
releases clearly sound like the distortion has been addressed and that the
compression is much improved. I recently bought an LP-100 Digital Vector RF
Wattmeter from Larry (N8LP) http://www.telepostinc.com/lp100.html . Among the
many functions provided in the LP-100, Larry recently added new code to allow
the user to measure the "effective audio compression" of a transceiver. The
technique uses an audio test tone pattern ( the one I used had a 1KHz tone with
alternate 50MS time segments with the levels 20db apart).
The RF power meter samples the power level 40,000/second to generate average
value. I used an "audio sound power meter" to measure the audio level of my
voice calling DX and then used the sound power meter to set the test tone to
the same level (Using a single level tone) into the microphone.
I tested the V2.062a code and got the following results:
Proc Setting Audio Result RF
Result Average Power
Off Slight Expansion
~8W
1 - 4 Close to no Compression
~9-10W
5 ~5dB Compression
~12W
6 5-10dB Compression
~13W
7 ~10dB Compression
~16W
8 10-15dB Compression
~20W
9 15-20dB Compression
~26W
I tested the V1.373b5 code and got the following results:
Proc Setting Audio Result RF
Result Average Power
Off Slight Expansion
~8W
1 - 4 Close to no Compression
~9-10W
5 ~5dB Compression
~12W
6 5-10dB Compression
~14W
7 ~10dB Compression
~17W
8 10-15dB Compression
~24W
9 15-20dB Compression
~31W
In all cases the peak power stayed very close to 39W - which is what I use to
drive my Alpha 87A to 1500W peak output.
As you can see from the results they track very closely - so closely that they
almost look like the same algorithm! There is a slight difference at the 9th
level on the Speech Processing but it is very minor (And might be altered if
the mike gain were increased). At a Speech processing level of 7 the talk power
is doubled from the level with the Speech Processing off. At the 9th level
there is roughly a 6dB (1 S-Unit) improvement in the talk power of the rig. I
usually stop at eight but there is no audio "background noise level increase
even at 9 (Maybe a very little hum). The audio sounds very good in the monitor
and the quality was verified by a friend. The talk power improvement is very
important in trying to work SSB DX.
I think the Orion V1 code has the best Speech Compression I have ever seen in
an HF radio and now it appears that the V2 code matches it! Thanks Ten-Tec!
73, Merle - W0EWM
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