Should contest rules allow and act upon 599K QRM reports?

Saturday, 6 December 2014

Alinco DR-135UK

On black Friday I puchased an Alinco DR-135UK for £99 from Nevada Communications.
I didn't bother with the USB programming cable as I have a number of prolific usb rs232 adapters lying around. The first one I tried was the one for my TYT TH-UV3R handsets. I downloaded software for the CRE8900 and bingo was able to configure the radio. I wanted to make the channel display useful, so I programmed the radio so that the channel display (for CW) shows the number of KHz offset from 28MHz i.e. Band A 28001 -> 28060 ch1 rx 280016 tx 28001 ch2 rx 280026 tx 28002 etc. You only need about 50KHz (28 -> 28050) tuning range for cw anyway. The reason for the 600Hz offset on the rx frequencies is that I have set my cw sidetone to 600Hz in the menus and the radio transmits the cw tone at this offset frequency, but doesn't shift the rx up by this amount, most HF rigs do this automatically but this one doesn't, so a manual offset on rx is required to work anyone. Putting this offset into the channel memory means you can forget this detail. For SSB I decided to program the channels in 2KHz steps as again this would enable the channel display to be of use. This time the channel display (for SSB) when doubled shows the number of KHz offset from 28.3MHz (band B) or 28.4MHz (band C) i.e.: Band B 28302 -> 28420 ch1 rx 28302 tx 28302 ch2 rx 28304 tx 28304 etc Band C 28402 -> 28520 ch1 rx 28402 tx 28402 ch2 rx 28404 tx 28404 etc The above programming methodology allows you to remember where the original channel frequency was once you have been playing with the clarifier. One of the major drawbacks of this radio is that you can only tune 10KHz either side of the programmed frequency for that channel i.e. Band C ch25 28450, you can tune 28440 -> 28460 using the clarifier. Trouble is it remembers the clarified setting when you move channel. It therefore pays to remember what the true frequency for that channel was so that you can return the clarifier to the centre frequency. This is easily done using the above programming methodology as you just double the channel number to get the correct programmed center frequency i.e. Band C ch24, radio frequency display says 28450, 24x2=48 so I know it has to be returned to 28448 to be centered. Band A ch2, radio frequency display says 28003, 2x1=2 (+600Hz) so I know it has to be returned to 280026 to be centered. Another drawback is that on CW there seems to be a time lag between the sidetone and the key. This is very off putting so the solution for me was to turn the radio sidetone off and use the sidetone from an external keyer. Luckily this radio can happily be used at speeds well in excess of 30wpm without the dreaded initial dah on PTT like the President Lincoln II (see previous posts). I'll round off by saying that the rx of this radio is really punished by incorrect tuning unlike normal radios. The audio quality seems to be very poor with even a 30Hz mistune. The audio of a station sounds terrible (dalek like) until it is tuned bang on. This means selecting the 10Hz steps and fiddling for a minute before the audio sounds good. The push step mechanism for the clarifier is round robin so it takes several key pushes to get the step to 10Hz and then back to 100 or 1000Hz when you want to tune away. Most people leave it on 100Hz as a happy medium, but then the audio sounds crap as you are up to 50Hz mistuned (see most youtube videos). I rate this radio better than the President Lincoln II V3 as the CW mode is useable (without the tx drift and the initial dah problems of the LII). SSB operators will prefer the LII as it has more toys and SSB doesn't show the bugs described above.

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