Showing posts from November 8, 2014

QRV TX/RX WSPR / CW op 630m 475kHz

 TX LED    MW..
Back QRV on 630m Medium wave after some changes now using the IC706 at 475kHz with a mod.
For RX a small bandfilter and preamp is improving sensitivity.
At TX side also a filter is used made of standard MW IF filters.
Then I got the QTX  running its optimal power out at 13.8V. about 30W RF
It was stable to run WSPR mode 2 minutes TX frames the airecoils heating up a bit loosing some 5-10W
The SM-FET did not even show a temperature raise so the efficiency  was high  approaching 90%.
The outside L/C tuning is easy tuning SWR to almost no reflection. Only it had to be done outside at the base of the inverted L 160 antenna.
Still a remote tuning is needed or a different approach  using toroid autotransformer to keep the tuning stable enough.

Na Wat knutselen 2 avonden   was de QTX weer in orde
En de tuning buiten weer afgesteld  SGV 1:1.1  tuner werkte ook nog.
Stemt heel mooi af op min SWR max power alleen is het wel lastig om dit buiten te doen.
Bij 13.6V  voorlopig   c…