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Reviews For: DYC-817 Speech Compressor

Category: QRP Accessories

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Review Summary For : DYC-817 Speech Compressor
Reviews: 25MSRP: 45
External dynamic compressor kit for FT-817/857/897
Product is in production
More Info:
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
VE2LRZ Rating: 2021-06-07
Must have for QRP FT817 - makes a difference. Time Owned: 6 to 12 months.
Building this was ok, make sure you practice your soldering skills if they are not up to par. The instructions are clear enough.

What counts really is does this make a difference? Well with my Yaesu FT817ND YES, it makes the difference in SSB between being heard or even copied and not being copied. I've done tests on various bands and it makes a difference. Many claim it actually gives you an extra S1 in copy-ability. This is a must have if you operate SSB on the FT817/818 and similar QRP rigs. Fully recommended.
W6KKO Rating: 2020-03-14
Great Upgrade for Yaesu 817/857/897 Radios Time Owned: more than 12 months.
Purchase Date: 2015
Cost: $45 USD shipped (Arrived about 7 days later from
Build Time: Around 30 minutes
Radios Used: 817ND & 897D

I use this with the stock microphones as well as with a Heil Improved Traveler Headset. The improvement is significant based on QSO reports. When switched on, the radio power draw goes from 0.7Amp to a 1.4Amp during SSB TX use on an 817ND.

P.S. I tested it on FM and was told to turn it off. The audio is overdriven for FM, based on the recording I heard of my transmission as well as reports. Works great for SSB.
KB3NWU Rating: 2019-07-02
Essential for 817 Time Owned: more than 12 months.
Bought this shortly after getting an 817nd. The difference really is amazing. Reports consistently say my signal increases at least 1 S-unit with much better audio, by simply turning it on. That is like turning your 5W rig into a 20W rig. The ability to easily throw a carrier is a very nice plus. It has "spoiled" me and I don't bother using my 817nd without it. Get one IF you still can. SOTABEAMS has been out of stock for awhile with "no due date yet."
DK2VS Rating: 2019-06-05
Great addon! Time Owned: 0 to 3 months.
Owning this speech compressor for just a few weeks, but I'm really glad. Tested with some OM.. switching it on and off makes a difference of about 0.5 - 1 S value, by S-meter. For the ear, it was the difference between "can hear" and "can't hear". I now always use it...

The price is fairly reasonable and it's not complicated to build/solder. Download the manual in advance if you're not sure. Someone experienced in soldering shouldn't have any problems.
E71DX Rating: 2019-04-07
Essential accessory for FT-817/818 Time Owned: 0 to 3 months.
I am using my FT-818 in SSB only for contacts via QO-100 with very low power (less than 1W). The small compressor increased my overall signal level significantly and I can only recommend the kit to anyone using one of these small transceivers.

The kit was assembled in a few minutes. You only need to solder the RJ45 jacks, 2 potentiometers and one switch.
KG9H Rating: 2018-10-08
WOW Time Owned: 0 to 3 months.
So I have had many many 817's and pretty much all but one needed more compression on SSB audio. They all sounded poorly when I had the SSB mic gain up all the way, but I ran it that way to be "somewhat" heard. So on a limb, I bought one of the compressors. I had to turn down the mic gain to 50 (what they suggest) and left the pots on the SOTA board where they were. I cannot believe how good this accessory is. Went from unreadabel to hearing me fine. What a great accessory! thanks for a great product! de KG9H
XE1EC Rating: 2017-11-20
It actually works ! Time Owned: 0 to 3 months.
Assembly was ok. Documentation is good and complete. Quality is superb.

It works quite well on my FT817ND. I did several tests and my signal went from almost not readable to clearly readable.

It is nice that you can disable the compressor at anytime with a switch on the side.

One added feature that I liked a lot is the fact that pressing the down button while the PTT is depressed sends a tuning tone !!, quite useful to tune a manual tuner or linear amplifier.
IW5CI Rating: 2016-12-14
It works with FT-1000 Too Time Owned: 6 to 12 months.
I use this compressor with the ft-1000 MKV and MD-100 mic. Every one say that the punch is great (better than turning on a 500W amplifier) and the modulation is even better.
G3TSO Rating: 2016-12-14
Now Working Well Time Owned: 0 to 3 months.
Following a disappointing start with this product, the company supplied me with a replacement pcb! This was quickly assembled and tested. Once I had re-crimped the RJ45 cable, all worked very well with a marked increase in talk power.

Having had a RF processor inside the Mic housing on an earlier 817, I find this just as good and more flexible as it can easily be removed

Earlier 1-star review posted by G3TSO on 2016-12-08

I purchased this kit from It looked prety good on arrival and only took an hour to add the extra components to the board. It drew the correct current when powered up, but when connected to the 817 it did not allow any audio from the Mic to reach the Rig. A little investigation revealed that all many of the SM components were dry jointed to the pcb. Looks like I have a Friday afternoon version! Do I waste my time fixing it or send it back? Hopefully when it eventually works it will be better than the manufacturing.
AB1QX Rating: 2014-09-08
solid addition to FT-817 Time Owned: 0 to 3 months.
Really make a quantum improvement on an FT-817's signal; easily an S-unit's worth. As another reviewer noted, the boost is better than the OBP, and, more to the point for me--not subject to RF pickup like the OBP was. Bravo!
Highly recommended.