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Reviews For: D-117/K4 Heavy Key "Chinese Army Key"

Category: Keys & Paddles

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Review Summary For : D-117/K4 Heavy Key "Chinese Army Key"
Reviews: 26MSRP: 75.00
Telegraph Key, Heavy
Product is in production
More Info:
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
N7TAT Rating: 2021-03-15
Great once modified. Time Owned: 0 to 3 months.
NOTE - I posted the same review under "Chinese K4" but am thinking that was the wrong category and possibly a different key.


I bought this key as NOS. It arrived well packaged in a somewhat beat-up original box with Chinese writing on the label. Inside the key was wrapped in plastic and fastened with a rubber band.

Overall Rating: 5

I picked a 5, not because this key is perfect (it is not) but because this key, with improvements, is a very nice key to use at a price that is reasonable. I'd recommend it to anyone who wants a stiff spring or can shorten the spring to lighten it.

Fit & Finish: 3

The bottom edge of steel base plate is not square so the key rocks on the table. The felt padded (cast iron?) weight is recessed slightly inside the base plate so it did not make contact with the desk nor help with the rocking. I fixed mine by adding washers as spacers so the weight would project below the base plate.

This is not a polished key. The plating looks fairly good but the underlying metal is a bit rough in places. There was a bit of a ridge around the plastic knob which I smoothed with some 600 grit sand paper.

The alignment of the upper and lower contact. They are spot-on.

Adjustability: 4

The spring is too tall and too stiff. I solved that by cutting about 3 turns from the bottom with my Dremel tool and cut-off wheel. The adjustment screws are all smooth with no sharp edges. Thread pitch is adequate. I found it very refreshing that I could adjust the trunnion screws for near-zero side play while having the rocker arm move smoothly up and down. On the Speed-X keys I've had, I could never get super smooth up and down motion without some side play.

Function: 5

I'm really loving this key. The action is very crisp with the key making a very refreshing click sound on both closing and opening. It is louder than my Junker but much quieter than the Kent I once had. The small mushroom shaped knob works well even with my big hands. The top of the knob is about 2" above the desk. I use European style sending (arm off the desk) so knob height does not affect me. YMMV.

Value: 5

I paid about $65 for my NOS key which in today's market is a fairly low price. Straight out of the box the key is has some issues but improvements are simple and very effective.

Junker vs K4

The Junker is a much better built key. Adjustments on the Junker are smoother and more predictable. The Junker works really well over a wide range of adjustments. The Junker is a quieter key as well. That said, the Junker is ugly and much harder to find. I was fortunate to purchase one NOS a number of years ago. The K4, once adjusted is a smooth functioning key. I find the Junker to be a slightly faster key to use yet the K4 is very enjoyable and side by side, the K4 looks better.
W1BR Rating: 2016-01-20
Quality control is the concern Time Owned: 3 to 6 months.
This is a very nice key with great potential. I have to be honest, this key may not live up to it's potential as received!! There are two major flaws that you might experience. If it wasn't for these flaws this key would be a solid 4.2 on the ratings scale. That isn't bad, but to be honest I have to compare hand keys to my Kent straight keys, and others which are true 4.5 rating or better.

First problem is the spring tension, which is a well know problem, with various fixes noted by earlier reviewers.

Second problem, which I experienced, was that the key base wanted to rock when being used. The metal base was WARPED! I had to remove the base, and use a large vise and framing hammer to straighten out the cast metal base. Not that the base is hidden beneath the fancy chrome cover! Removing six screws releases the base (chrome cover, with the cast metal base beneath.)

Once the spring tension was addressed, by removing a few turns, and the base hammered to being as flush as possible, the key was elevated to an at least a 4 on the eHam scale. Now, a 4 is NOT a bad review!!! There are many hand keys that are more precisely engineered and that may feel better to your fist. I am happy with the outcome for the K4, but I am disappointed that I had to expend effort to modify manufacturing over sites or sloppiness. This can be a decent key, with a good feel, but you may be a bit disappointed with one that wasn't representative of the best of the litter.

My gold standard is the Kent KT-1, just for some comparison.
K8RXB Rating: 2015-10-21
Good key for British (European) style sending Time Owned: more than 12 months.
As an addition to my review of my K-5 key posted in January of 2015, I would add that the key works very well for both American and British (European) style of sending. I have now totally converted to the British style and find this key to be rock solid at the edge of my desk when used in this manner. While I do at times look at a Kent or Begali Blade, this key serves my purposes very well at this time. Whiie the K-5 may no longer be available, the K-4 with silver contacts is still available from Morse Express.

Earlier 5-star review posted by K8RXB on 2015-01-14

I have used my K5 from Morse Express for a few months and find to to be excellent. The key arrived quickly, and like many others, I found the spring to be a bit tight. After carefully removing the spring and compressing it in a vice for about 20 minutes, the action seemed just right to me. I would recommend the K5 to anyone looking for a great straight key at an attractive price. I would also recommend Morse Express as a fine company.
K1FPV Rating: 2015-01-15
Great Key For The Price ! Time Owned: more than 12 months.
Terrific key and with my arthritic hands, it is very comfortable especially since I hate keyers. I have a Vibroplex Bug, but don't use it much.

The only bad things I can say about the key is if you use it with a cathode keyed boat anchor, the contact point is mounted on a chrome metal plate atop an insulator and with cathode keying, it bites you! ;-)

I put a small coating of black liquid tape on it to eliminate that problem. The other complaint I had was the cable with the RCA phone plug on it is flimsy. I replaced it with a nice rugged black coaxial cable and chrome plated 1/4" phone jack.

Reliability, hand comfort, weight, and general feel is terrific. Great key!

Bill, K1FPV
N7SCC Rating: 2013-11-21
K-4 "Chinese Army Key Time Owned: 0 to 3 months.
Excellent Stright Key! Paid 69.95 dollars plus shipping from Milestone Technologies, USA. Better deal and quality than E-Bay purchase. This Key is a "5". It's heavy and well built. Choice of Brass or Silver. Even through the pressure spring is very tight-- this key is the best at sending CW that I've owned. I agree with another reviewer that said, "Get one while you can". Supplied with a 1/4 phone male plug; the only negative I can see with this key is the 3' cord is not shielded-- I haven't had any problem--but, don't let that keep you from purchasing this key! I will purchase another Silver K-4- don't worry- the pressure return spring can be adjusted; but, I'll only adjust mine a sight bit. This key is a great value; heavy and actually well made, full of Chinese history, includes the Navy Knob, heavy cord; this Key's quality is not cheap! For the price, "Get one while you can." Thank You, Milestone Technologies.
W8IJN Rating: 2013-07-09
My Favorite MilSurp Key Time Owned: more than 12 months.
I have long wondered about these Chinese keys. They're available all over the web from various sources but the price, well, let's be real: I'm not reallly that interested in a key that costs me as much as an two-bander HT.

Then, one day out of straight-up goofiness, I pulled a winning eBay bid for a complete Chinese military surplus station from a fellow in Canada. Included in that set (which was two very heavy boxes full of all kinds of Maoist swag) was a D-117 Morse key, documented & approved by the Central Committee some time around 1966.

I discovered immediately that the D-117 is lower to the table top than many of my other military surplus keys and because the finger-grippin' parts at the end of the key are big, round & massive, a person like me, with essential tremor, can control the key better, even to the point of making straight key CW fun again. (For keyer/paddle CW, I use a Begali Simplex, maybe the best paddle on the planet.) I can sit at the key for quite a long time (for folks with ET that can be 15 minutes or 5, which def takes the fun out of it.) And I can get by sending at reasonable clips (13-18 wpm on a guess).

I was so impressed with the D-117 that I bought two more, one of which sits with the "real station" (the Icom stuff &c), replacing the JRC KY-3A that I've used along with a British WWII marine key for nearly 40 years now.

In all, it's a fine key, probably made by someone who was hungry & probably overworked in horrible conditions (during the Cultural Revolution). I think of that often as I consider the work that went into the D-117: all the chrome plated parts, the metal & machining, the plastic insulator block, the screws & threads & knurled nuts & all.

Whoever built this key deserves a hug. And to know that this old gringo is not mindless of the way this D-117 got here. And it's a good key too.
K3HVG Rating: 2012-06-02
A fine straight key, indeed. Time Owned: more than 12 months.
I have a number of these keys, received as part of the 102E radio sets I've bought from Red Star. As has been noted, these early K4 keys are very nice and constructed well and were manufactured in the 1960's. I have had to do the spring mod as I did not (apparently) receive spare springs with my various 102E systems. One thing I note is that all come with the chrome base but the plastic key body may be either black or an off-white color.
The PL-55 plug generally must be burnished/cleaned with Scotch-Brite or Brasso. No issues whatever and when bought singly are a bargain. I cannot speak for the ones mfg in the 1990's, however.
KT4H Rating: 2011-02-07
Very Good Value Time Owned: 3 to 6 months.
You get what you pay for but this one is a good deal if you get it new for around $40-45 including shipping. I did not like mine at first. The finish is only so-so and, like many others have stated, the spring is way too stiff. However, after shortening the spring to the point where the set screw needs to be used to add tension, the action is excellent. It now has a great feel. I rated it based on what you get for the money, and this one seems to be an excellent deal.
AD8B Rating: 2009-11-30
Replace the cable Time Owned: more than 12 months.
This is a followup to an earlier comment.

My new rig started locking up when using an amp after connecting the K4. A quick check found the supplied cable is not shielded.

I'm still happy with the mechanics of the key.
DV1UBY Rating: 2009-10-04
Great Morse Key! Time Owned: more than 12 months.
These Chinese Military Heavy-duty Morse key is a great addition to your shack. I have 2 Chinese Military Heavy-duty Morse key in use right now, I bought it brand new in Hong Kong, it has a silver contact, it has brownish-red heavy duty plastic knob, heavy duty spring, chrome finish base, and does not skid. It's really heavy and nice to use. The quality is good and as a traditional Morse key user, I recommend this one. Nice appearance. Also, checked the enclosed manual and it says : Date of Manufacturing: 1954 :D