Tuesday, December 16, 2014

QRP Radios-KN-850

I noticed on ebay today the KN-850 up for sale. I purchased a KN-920 quite some time ago and had trouble with it and never got any help with an exchange, partial refund or a replacement radio for the one I had.
These and the KN-Q10 radios and others are designed by BA6BF. The KN-Q radios have taken off in the past and offer both cw/ssb at 5 watts.
The KN-920 was a nice looking radio but during a qso the radio shut down and shut down my power supply. I had to reset the power supply, turned the radio back on and then noticed the magic smoke that is supposed to stay in the radio slowly making its way out and leaving a smell behind on exit. Turned out a final gave out and traces burnt up. I was sent some new finals and asked to replace them.
Once replaced I tried the radio, power down to zero, keyed the radio up into a dummy load using cw and no problem, slowly cranked the power up and ZAP, there go the repaired traces once again and the magic smoke once again escaped.
I tried 3 sets of finals with no luck.
The seller at Aliexpress ignored my emails and refused to make a partial refund or any kind of return to me despite the Aliexpress policy, so I was not a happy camper needless to say.

I asked the seller today about the KN-850 as it has been reduced in price about his return policy and how well this radio works.
 His reply was this, and I did ask who the builder was:

" HI,, this device made by one Ham, this is the second version, the first version sold several years,
this version is better , and sold server month very good
we provide tech support for life, and or return for repair .
thanks "

So I am guessing the KN-920 was the first version and this is the upgraded better version.
There are many Chinese radios out on the market now offering all kinds of bands and modes, but quality and returns can be an issue as many of us have experienced. The other issue is the cost of these units compared to the big names who have proven themselves.

 The KN-850 covers the original ham bands, plus 6 meters (no FM). So no 30,17,12 meters on this unit.


http://www.ebay.ca/itm/121514100347?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649







3 comments:

  1. The MDS SD Series are industrial wireless solutions that provide long distance communications over licensed radio bands, http://www.remotesiteproducts.com/

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  2. It looks like you made the right decision regarding the KN-850. This is from the CRKits list, November, 2014:

    "BA6BF has completed the testing. The VCO for 6m band is a bit unstable during TX and the signal will sound a bit trembling. As there is no plan to add a shielding box, it will leave to end customer to modify or bear with it.

    Again the HF bands sound good in both RX and TX."

    73,
    Cait, K9NI

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  3. OK, I have the KN-850. The price came down to the point that was too low to ignore. I also have a KN-920 which, once again, cost me very little. The KN-850 is an entirely different radio. In the roughly three and a half years that the KN-850 has been on the market there have been three versions. As seems to be typical of Chinese manufacturers they do not change the model number even when significant changes are made. We've certainly seen that with the Youkits TJ5A.

    The radio is well under half the size of the KN-920. This rig also puts out more power than the KN-920, rated at 3-15W out. The band coverage is 6-80 meters excluding the WARC bands and 60 meters. It's a six band radio.

    The comments I quoted above by Adam Rong are possibly still true. It's a very good HF rig. It has a really good DDS implementation though the noise floor is still not as low as the TJ5A, which is truly excellent in that regard. Sensitivity is quite good as well. It has six programmable SCAF filters which really is nice for CW and digital operations as well as on SSB when a band is crowded. Unlike the KN-920 there is no AM or FM operation even on receive. On HF it works very well, putting out rated power and getting very good reports on the air. 6m is still problematic, putting out 3-4W at most and lacking a bit in receive sensitivity. It also has a few birdies which are quite loud, something that is not true on HF. If you think of it as a 5 band HF rig you'd probably be satisfied with the performance. On 6m I haven't had the opportunity to use the rig during a band opening so I don't know if the stability issue is truly fixed. I know that before the price drop Faymo Trading was selling the rig with a TCXO added so an older KN-850 on the used market without that addition could well be problematic.

    Regarding warranty service, the manufacturer does claim to offer it. The problem is that the various Chinese dealers offering the rig have widely varying customer service, ranging from none at all to quite good. I think you saw that with your FX9A. When you got help from Windcamp (a company that does a good job) you got the service you needed and ended up with a decent radio. I'm not surprised you did not fair well with Ali Express. Personally I try to deal with a handful of Chinese merchants with whom I have had good experiences. I also asked a lot of questions before I bought my KN-850 and received prompt answers in clear English. That certainly helped me feel comfortable with the purchase. I paid $279 for a new radio shipped to my home. Delivery time was ~2 weeks.

    Speaking of English, the manual has some of the most broken English I've ever seen and it is woefully incomplete. There are no schematics, no pin values/connections for either the ACC or ATU connections, no information about the USB port or how to set popular software for rig control, which is an advertised feature of the rig. The only clue is that, like the KN-920, it uses an Icom HM-36 for the stock mic, so digital operations should be easy to figure out. Connecting my Rigblaster Nomic and getting it going on fldigi is on the agenda but I haven't done it yet.

    Another problem is CW chirp using the built in keyer. If you use an external keyer or a straight key the problem disappears. I suspect the issue is probably similar to the firmware issue you probably experienced with the Xiegu X1M. On that rig lengthening the CW delay was a work around. I need to try that and see if it works.

    Overall this radio has some strong points for an inexpensive radio: receiver performance (yes, better than the KN-920 by a fair bit) and filtering. Indeed, while the SCAF filters don't compare well with crystal filters or a well implemented IF DSP filter they do a good job, as in certainly better than the single CW filter in the Youkits TJ5A, a radio I really like overall. The weaknesses are 6m performance, the CW chirp, at least with the default settings, and the poor documentation. Dollar for dollar you do get quite a lot of rig on HF for the money.

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