Jd1,
My original M-802 was delivered in 2004 with the speech
compressor On, and I turned On the speech
compressor on my second M-802 via
software (CS-802)...
So, I cannot help with your query, except to offer the
advice to NOT worry about having a front panel capability to turn it On and Off...as you will NOT need to turn it Off...and this is not just some cruiser BS, but I have actual data...
Or send your
radio to Gary at Dockside, and have a pro do it...the tiny surface-mount devices in these modern radios are NOT conducive to amateur techs /
novice solder'ers....
Quote:
Originally Posted by Jd1
I have searched and searched for information on the modification needed to allow front panel activation of the built in speech compression system. Alas, I have been unable to find this information.
Some dealers (Dockside comes to mind) will do this mod at a reasonable cost when you buy a new M802 from them but this leaves a lot of people who are not able to activate speech compression.
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Now, if you desire the nitty-gritty details, this has all been discussed before....
IC-M802 Compression
Bottom line:
The M-802's "speech compression" is done digitally inside the DSP modulator, and as such is very clean, and does NOT introduce distortions / artifacts, nor does it contribute to IMD, nor adversely affect transmit bandwidth nor spectral purity...
(technically, according to lab tests, the
radio misses the spectral purity spec by about 1.5db at 150 watts out with the speech compressor On....but does pass at 100 watts with it On, or at 150 watts with if Off....but even missing the spec by 1.5db, still places it 20db+ better than ham rigs or older/out-of-alignment maritime rigs that you hear on the air....so no worries here...)
Please understand that this was designed into the radio to be used primarily On....as the peak-to-average voice ratio programming of the DSP modulator is designed for this "speech compressor" to be On, which is certainly noticeable by the rather poor "peak-to-average" voice (poor "talk power") when the speech compressor is Off...
Further understand that this is NOT what modern ham rigs use (many using crappy ALC-based, distortion-inducing, "ALC-based speech processors", and others use distortion-inducing audio-based speech processors, etc...), but the M-802's DSP-based speech compressor actually improves audio quality as well as peak-to-average ratio....
The M-802's DSP speech compressor has no effect on
PACTOR modem use, assuming you set the
modem drive levels correctly....
If we were talking about a ham rig / a rig with an adjustable mic gain control, or a radio connected to an ext. 1500 watt amplifier and multiple directional antennas, etc. then I would certainly agree the ability to easily/quickly turn off the speech compressor, would be a necessity.....but that is not the case here...
The only caveat here would be if you use the radio near a noisy
environment, such as near a running
engine, etc....and with the "speech compressor" On, there can be some background
noise pick-up that can be disturbing to some others listening to you (poor operating practice!)....
So, if this is the case in your situation, then I understand the desire to be able to turn it off...
BTW, there are some videos and threads that will help you understand the M-802, HF-DSC
communications, long range
Marine HF comms in general, and
offshore weather access, etc...
Have a look...
https://www.youtube.com/playlist?lis...rC-8QKVyMb4tVr
https://www.youtube.com/playlist?lis...ga2zYuPozhUXZX
https://www.youtube.com/playlist?lis...ZDo_Jk3NB_Bt1y
https://www.youtube.com/playlist?lis...zdjTJjHlChruyY
http://www.cruisersforum.com/forums/...tc-133496.html
http://www.cruisersforum.com/forums/...ll-114734.html
http://www.cruisersforum.com/forums/...os-141406.html
Offshore / Hi-Seas Weather data / forecasts
I hope this helps...
Fair winds...
John