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Re: Sotabeams speech compressor vs The One Big Punch by W4RT

 

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Mike,

Thanks for your reply. ?I thought I opened up the OBP mike and saw only a few parts but that was 15 years or more ago. ?I will do it again just to see. Thanks for your info on it being a real speech processor. ?I rarely used it. ?

I have used a common mode choke about 10 feet from the rig on the coax to the antenna as I have had rf feedback on a few of my other QRP radios in the past. ?I found it necessary even on my KH1 and CFT1 while in Florida at a rented condo with stucco siding and metal railing around the deck. ?The choke stopped it. ?I see some of the feedline coax from some vendors now can come with a series of toroids close to the transmitter end as a CMC. ?I bought a kit of same from the Wireman at the Florida HamCation this year but haven’t built it yet. So I question that your feedback came from a poorly shielded mic cable. ?Yaesu has good shielding in their mic cables. At least that is my opinion. ?If made in China I have seen poor to no shielding on mic cables. Japanese back in the day were pretty good.

I keep my FT 817 as a souvenir (just like my TenTec 515) of my early QRP days. ?Too many rigs but I eventually purchased every add on option for the 817 that the Brits made….. what fun I had when working. Now retired 10 years and have less time (and energy) than I had when working. ?Ha!

I also have a stand that holds the 817 on top of a LDG Z 11 tuner with batteries inside the tuner. Just a nice small stacked rig with tuner that covers all bands and VHF/UHF. ?What a radio! ?Just too many button presses, rotations, and small screen. ?The same radio with a larger screen and a tuner would be a great radio and would sell well.

Again, thanks for your comments.

Dave K8WPE


On Apr 7, 2025, at 12:42?PM, Mike via groups.io <mbmadden@...> wrote:

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Hi David,
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I have both the One Big Punch (20 years old now) and the SOTAbeams speech processor (labeled DYC-8x7).? The OBP is a real speech processor, not just passive components.? They both work.? I think the SOTAbeams gives a louder signal, from on-air testing with remote SDR's.? (There were some other mods floating around the internet to change components in the stock mic to implement a passive high-pass filter, but this is something separate.)
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The OBP suffers from RF getting into the speech processor in the mic, causing a feedback squeal.? Care needs to be taken to isolate the mic as much as possible, but this is hard in the field when the antenna is often feet from the mic.
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The SOTAbeams processor seems to be less susceptible to RF back into the unit.? But it has happened.? I tried using a flat cable to connect the mic to the processor to reduce bulk in the pack, and it was particularly susceptible to RF back into the unit.? The stock curly microphone cord has better isolation.? ??
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Care needs to be taken with both units in reducing the SSB mic gain setting on the FT-817/818.? My setting is around 30.? I listened to myself on remote SDR's to find the right setting.??
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When it is all set up, I get the effect of 1-2 s-units of gain from the SOTAbeams processor.? I concluded this by using 0.5 Watts with the processor on, compared to 5 Watts with the processor ff and mic gain returned to 100.? 0.5W with speech processor was still louder on a remote SDR than 5W without processing and mic gain set to 100.? Greater than 10 dB of effective talk power.?
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73
Mike N9OHW
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