* June 2007

Can we build a decent 1.5KW 6m amplifier on a budget of €500 ?

During coffee time at Henk’s, PA3GCV, (www.pa3gcv.nl, 160 meter freak) we got the idea to fill our sparetime efficiently with a sensible project. We decided to build a 6 meter amplifier just for fun as the breeding will out. Our first thought was to use a 4cx250B, however, I came to the conclusion that this tube was out of date and we searched the Internet for better materials. A GI7B looks quite nice and fancy, but we had something else in mind. So would two of them do the trick? No, even two of them couldn’t match our expentations and so we decided to concentrate on some bigger fish such as 8877s. The availability of certain types of tubes made us look at the Russian tube market. Who seeks shall find, how about a GS35?

After studiying a lot of data we reached the conclusion that we wanted to use the triode GS35B, 1500W output (400 Watt is also possible for qrp). The price is good and parts are easy to obtain, but if it will meet our budget that remains to be seen.
4 kV dc, 0.75 mA should do the trick, but if it will fit into a nice case is something to be seen.
The design of Bill, K8CU, will be used as basis; grid circuit, anode/grid meters, security systems etc. will be partially borrowed from G3SEK. The LED vu/power/grid etc. meters will be designed by ourselves. Due to our restricted resources we will make the tube socket ourselves after the design of W4ZT. Afterall, time is not the issue…
We will see which way the wind is blowing.

* 04 July 2007
Started With a Kiss?  (Hot Chocolade) We boltly go where we hadn’t gone before… by sawing and milling a piece of alu the kick off was given for a huge project. See some pictures.

* 04 July 2007
* Build a Tube Socket (update 27 july 2007)

* 07 July 2007
* Build Triode control board (update 9 aug. 2007)

* 10 July 2007
* Build power unit (update 9 aug. 2007)

* 10 July 2007
* Build LED display board

* 22 July 2007
* Blowers two airflow  (film flash)

* 22 July 2007
* 'We Got Him'

* 1 aug.2007
* HV (update 30 aug. 2007)

* 12 aug.2007
* Experiments (update 12 oct. 2007)

* 18 aug.2007
* Miscellaneous (update 15 oct. 2007)

* 02 febr. 2008
* Cabinet (update 19 april 2008)