6m Transverter and Linear construction project
DF2FQ 6m Transverter
Started Summer 2006, the IF is on 10m and is rated at 6w output. The PCB by Holger Eckardt DF2FQ is very professional and easy to build. Instructions are in English! My only criticism is that PCB holes are plated through – excellent except you tend to destroy any component you put in the wrong place!
First stations heard were from Serbia and Hungary. Output was initially only 300mW. Extra capacitance was needed in the ALC circuit and it now puts out 5-6w easily after increasing from 10pF to 110pF. First QSO with Colin M5AEH suggests it works well on SSB. Harmonic output was tested and is better than -50dB. Since then, I have built a linear amplifier to take output to 60w.
See Holger’s web page at http://www.df2fq.de/index_eng.html
Spectrum TA6SB 6m Linear Amplifier
Built in February 2007, it takes about 4w input and transmits 60w out using a single BLW60c RF power transistor. The kit was designed by Anthony Nailer G4CFY. It comes with a die-cast box with a LED and is either on or off with no other controls. The amp worked first time, was easy to build and align and is well within intermediate level construction skills.
I found soldering difficult visually because the PCB is tinned and very reflective. I would have preferred more details about how a kit works (Walford kits are a particularly good example of this). Harmonics were tested and found to be good at better than -50dB. However with Classic FM being on 101MHz this is quite a challenge for 6m. I put a couple of ferrite beads on the +13.8v line as connects to the board and will try further measures to reduce that harmonic further.
See Anthony’s web page at http://www.spectrumcomms.co.uk/amateur.htm