Monday, 16 May 2016

Feb/March – building a 70MHz transverter





Back in the 1980s’ I was very active on 70MHz from home with a homebrew transverter (Jewell and Powis) feeding a single 4CX250 for legal limit power.  I had decided that since 144MHz UKAC was going nicely that I could fit in the four 70MHz contests, again probably just in the AL section.  So the transverter was found (in the loft again) but I quickly realised it only had 0.5W output – enough to drive the ‘250 but not enough for the contest.  Probably also a bit average on performance so I decided that a new transverter would be a good thing to bring me up to state of the art.  One quick email to G4DDK and a new unit was in the post.  Unfortunately, I didn’t have enough time to get everything working before the 31st of March but I was ready to go for June.
 

 

 
 
 
 
 
 
 
 
This is the G4DDK Anglian transverter in a 70MHz version with the 7W amplifier module on the rear panel.  The box and cabling dates from 1985, just needed a quick re-wire of the DC, add some SMA plugs and away it went.  For the record, 7W out with second and third harmonics >-66dBc - impressive.  The front end is some modern device so no need to worry about the system noise figure and 24dB gain.

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