Tuesday, April 23, 2013

Xiegu X1M: Review

"I also received my X1M from the manufacturer yesterday.    I will do a written review,  while video would be better, youtube is blocked here and so I did not bother to make a video, play with the VPN to upload it, etc.    I can do that during the weekend.  
Initial opening the box observations:
Unit arrived in bubble wrap, no outer box or other packaging.   Instruction "manual" is 1 page front and back printed, which gives basic specs and menu functions -  good enough that even an inexperienced ham could be up and running.   The units that I am procuring are fully assembled, not kit form.    The box contained the radio as well as a hand microphone wired for the radio.  It also included a phono jack for CW key (wire yourself) and a power jack (wire yourself).   I wired the power jack, plugged it into the ps and the radio and turned the radio on  -- nothing.    OK,  quick inspection of the power plug reveals that the barrel is too wide and the pin is too narrow - the plug fits snugly into the jack, but the inner barrel does not connect to the inner pin.    I unplugged my AT-100 auto-tuner (that is wired with similar barrel) power jack, plugged it into the radio just to try things and the radio turned right on.  
Radio is light weight.  All metal enclosure and looks to be well shielded.   Rear panel of my unit has "metric threaded" SO-238 RF connector, and I was able to find some PL-259's that fit just fine.  The Amphenol connectors that I have did not fit well...so...it's easy to swap out a different rf connector, or get a simple adapter with the right threads to convert it to N-connector or BNC connector etc.  
Radio has  a small built in speaker.  Volume/audio  is adequate but not super loud - probably better with external speaker or use headphones.  While the mic looks identical to a ht speaker-mic, it is not wired that way and thus is used only for TX audio.   The mic has a red LED on it when in TX mode to show transmit.  The LCD display will also show a  T or R icon when in transmit or receive.  
Initial operating observations:   Radio has a built in preamp that really helps receive.  The sensitivity is around 0.45uV which is less sensitive than my FT-857  -- i dont have other QRP rigs to compare it to, but it's not in the same class (price or performance) as a K1, Scout, 817D, etc anyway so i suppose it is really more than adequate.  There are dedicated bandpass filters that switch in and out and those seem to really help selectivity (as expected with an SDR). 
Tuning - the first thing you will want to do is spin the dial.   OK, the VFO knob feeling is clicky clicky knob, think of it like a "select" knob on the 817/857 or Alinco DX70 radio if you are familiar with those.    Or, if you have owned QRP gear, think of it like the Uniden 2510/2600 or RS HTX-100 main tuning knob.  It is not a "smooth VFO" knob.  The knob clicks.    And, like every other knob of this design , it too occasionally skips a beat or two, so you have to watch the VFO when tuning up or down band. I would have preferred a smooth vfo tuning mechanism, but can't have everything.     The VFO knob has  rotate function and a push in function. The push in function is used to "set" certain parameters, such as tuning step once the step has been selected.   
The LCD display is green backlight and fairly easy to read considering small size overall of the unit.  Frequency is the main use for the LCD display, as is TX or RX function, pre-amp on or off.   
There is no S-meter or RF(output) or SWR meter on the LCD display unit.  
Tuning resolution can be set to Mhz, 100 Khz,  10 KHZ,  1 Khz, 100 Hz,  10 Hz, and 1 Hz.   Yes -- pretty remarkable but remember this thing is all DSP driven.   1 Hz resolution is probably overkill...but anyway, it's there if you need it. It's a little 
Modes are USB/LSB/CW.  No AM or FM or FSK.     You change modes with one of the front panel push button switches.  Pushing and holding one of the switches will put you into Menu mode.  Pushing and holding other switch will turn the preamp on or off.    
You can set the BFO frequency for these modes within the setup menu (9 menus are available for various tweaking, mostly dealing with the SDR aspects of the radio.
There is no obvious POWER OUT or MIC GAIN or ALC adjustment as noted previously.. 
I am mostly a CW op and the bandwidth in CW mode is fairly wide ... maybe 1800 Hz bandwidth.  Did not have time for measuring it but it is certainly not a narrow filtered receiver as judged by my ham ear.   
On SSB it plays nicely and was listening to some of the Sichuan earthquake H&W traffic last evening.   
I like the gen coverage receive, but without AM detection, it is just so-so listening in on the shortwave bands unless you zero-beat and eliminate the heterodyning.  Good news is that the DSP is super stable so the thing doesn't drift like the old capacitance style vfo's.... had to keep one hand on the tuning dial while listening to London...Once set you can at least hear and understand the broadcast (bandwidth a little narrow for AM too)
Have not done much advanced testing - sensitivity, selectivity, audio and power out, etc... will report more when tests are completed.  
I feel it's important to represent this rig as it is.... not mislead.  Share positives and negatives... provide feedback to manufacturer for improvements, etc.  The unit I have, is serial number X0087...white glue on sticker.    Would be interesting to compare production differences with others.    
As indicated previously,  I have placed an order with the manufacturer and will keep posted on committed delivery dates to me, and then onward shipping, pricing, etc. for those who expressed interest.  
More to follow.
Joe K7JOE/BY1"

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