Now It's time to build an old scool tube transmitter.
It's the meaning to use this tube transmitter at the next JOTA (november 2015) as a legal "event transmitter".
There are some restriktions when use a event TX, total output max 15 watts.
But we use long cable, we need 15 watts at antenna, so we use about 30 watts for TX. (that's maybee more at ant..)
At This page I trie to make a record of the build of this TX.
The transmitter (TX) is build up around 3 tubes:
ECC83 as oscillator
QQE03/12 as Driver
QQE06/40 as output tube
Also I dicieded to make it stable with a pll circuit.
Nowadays you have to...
Drilling holes in topplate for sockets so the tubes can be mounted
Inside the box...
And it's working at a frequency of 105 MHz. No low-pass filter, so a lot of spikes shown at the spectrum analyzer.
second tube testing. see it glows..
Bit hard to see, but it dilivers about 10 watts in a 50 Ohm dummy load.
And again no low-pass filter so it looks nice at the analyzer screen.
More to come.....