G3YYD |
The licensed on 19 November 1969 and was first activated at Aldenham School on 21st in a QSO with G3YJO who was in another shack at the same school some 500 metres away. Signals needless to say where end stop. Equipment in use was the RF portion of an ex-army 53 set with a pair of 813s driven by a 807 with a homebrew screen modulator. The PSU was also homebrew with about 1500v on the anodes. About 6 months later I converted the RF section into a passive grid linear amplifier on the acquisition of a KW2000B. This was an
all valveSSB/CW transceiver produced in the UK by G8KW, similar to the Collins KWM2. It was soon modified first to stabilise the voltage to the VFO valve's heater using a Zener diode and to replace the OA2 neon 150v shunt stabiliser with a Zener diode plus transistor. There was still considerable warm up drift but at least when my mother was cooking the rig no longer drifted up and down the band as the cooker's thermostat clicked in and out! |
Being a 80m SSB DX chaser from the start, I soon added RF speech clipping to the KW2000B's IF circuits. What a difference it made almost nobody knew about RF clipping in those days giving me a 6 DB advantage over AF processors. One downside was the 813 valves suffered melt down with the higher average power. Its replacement was a Heathkit SB220 with a pair of 3-500Zs, a real bargain at £175. This amplifier served me faithfully with the original valve until Dec 1999, when the primary of the EHT transformer failed. In 1974, having started work after university, I replaced the KW2000B with a Drake T4XC/ R4C (£500). What an improvement in RX performance. This was to remain my HF rig until 1998 when it was replaced by a FT1000MP with all the filters (£2400). In 1985, I purchased a FT290R and a 4CX350a added to this in the
later 80s. I spent a lot of time in the late 80s on 2M CW. Followed in the 90s and till today on HF CW. I love to DX on CW as well as ragchew at 30WPM. |