Ten Tec 40 meter CW kit

This page shows a kit/project I started then had to put on hold while I moved house.   Now its finally finished I’m enjoying using it.

Since I bought this kit Ten Tec changed hands twice and they no longer sell these.  I had been planning to build 20 and 30 meter versions too.  A similar radio is made by Oak Hills Research, the OHR100a if your interested in building a nice one band QRP CW only radio kit.

As it arrived packed up.  All the components were stored inside the case.

CWKit_wrapped

All the parts to be assembled.  Everything in the picture below was inside the case.

allparts

Close up of the board.  Quite a few components to be soldered into place!

board1

Now the board with all the components added.

40M_board_complete

Board installed and tested ready for alignment.  After I installed the board into the case the VFO frequency changed and was too low, down about 6.5Mhz, so I re-wound the VFO toroid and got it closer to 7.000-7.080 by making the turns really tight together,  I then spread and compressed the turns till it was exactly on 7.000.  This took a few attempts to get right.  Once I was sure it was where I wanted it to be I put some hot glue over the windings to secure it.  I also made sure the hot glue didn’t cover the polystyrene capacitor beside the coil as the heat from the glue would have permanently affected its value and the VFO would be off again.

top

Another view of the finished radio.front_top

I made a rather crude set of connections to the key to do some testing and some more alignment.  At this point the power output was about 1 watt, done a couple of CQ calls and got a reply, (thanks Jeff, WB2RAT), we had a nice QSO and during that I peaked the RX for maximum signal.  Alligator clip leads on the key to the back of the connector in the radio do a FB job, hi hi!  The picture below was exactly how I had it all set up for that first QSO.

1st_qso

After I was happy with everything and peaked the transmitter to about 4.4 watts it was time to put the cover on and call it complete.

finished

Front view.  I have a chart showing the numbers that correspond to the frequency.

front

Now I just need to find some time to get it on the air again and make a few more contacts!

I am surprised how stable this radio is.  Very little drift during the first few minutes, and none noticeable after its been on for only a few minutes.  I’ve built other radios in the past that needed 20 minutes to warm up before they were “stable-ish”  With this little radio you pretty much turn it on and use it!

Thanks for reading my page about this kit.  Hope to meet you on air some time too.

73 FER NW, DE AF7DK

 

 

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