Amateur radio station since 1993
My transverter 144/28 with high dynamic range
see at 2004 years Javornic
144/14 design by S53WW
and designed my XVTR.
Transverter with high THREE-SIGNAL DYNAMIC RANGE :
- Local oscillator (with temperature-compensated) 116 MHz. Phase noise LO is better -150 dBc/Hz at shift of 10 kHz and better -145 dBc/Hz at shift of 1 kHz ! LO for all my XVTR (144,432,1296,6cm and 3 cm) by UA3AOH !
- High IP3 Level frequency mixer SYM-18H (Mini-Circuits, LO +17dbm)
- High IP3 level in the receiver low noise stage with 2xBF981 and BFG591
High selectivity with 4-stage helical band pass filter (from FM-301 Hungary FM stations) - more 70 db rejections outband 144-146 MHz. Also final low pass filter rejection spurious and harmonic of more than 60 db (filter LPF also from FM-301 with modifications).
Different betwen PRO Version and Light Version - in "Pro" use second unit for only TX-stage : second filter , TX stage and second high level mixer. In "Light" single filter and mixer use for RX and TX.
The TX power of the transverter can be adjusted with the potentiometer on the front panel - aadjusted high level balanced stage 2xBF961(981) .
PA: use RA13H1317M
about output 20 W , Circuits level control : 2...20W
The output power, input IF power and SWR is indicated on a meter in front panel.
Modifications in 2011 :
- new design TCXO for LO unit
- new 1 stage with high reliability GaAs MESFET FH1-G
NF of new front-end ( FH1G in 1 stage)
You can see fabrication stages similar to mine XVTR for RA4SD
PA module RA13H1317M - power out 30W