Amateur Radio And Electronics Site
Have thrown together some parts on a plank here. The idea is to make a “lean” power supply to test my crowbar circuit.
Output is 630v with the current limiter (spot light bulb @ 120watt). And the capacity of the filter capacitors is about 1100uF.
This should be enough energy for the preliminary circuit tests.
Crowbar test supply
….to be continued if I survive 
Here is a line of homebrew circuit board that I have made for a amplifier project I am working on. (Which by the way takes forever to comlete )
These boards are designed by Dominique F1FRV which have laid down a tremendous effort in designing these boards.
Dominique has done some minor changes to the design since these boards were made, so cards made by his latest instructions will look a bit different from these.
I have put my wspr beacon on the air for a test after the latest modifications. And so far it look promising.
Here is a picture of the mess
Picaxe wspr beacon. Bottom: Picaxe and DDS-60 :Top from right: 10MHz LPF, tripler and amplifier for clocking the dds-60 @ 30MHz
Here is a small update regarding my band hopping picaxe controlled wspr beacon.
I took the beacon of air the other day to do some revisions to it’s circuitry. And in this context figured out that I was in need for a filter to clean up the square wave shaped signal from the 10MHz reference oscillator, the GPSDO MKII. I did a little googling and found an interesting circuitry drawn by Jerry Mulchin – N7EME. The reason for needing this filter is that I have a passive frequency trippler for clocking the DDS-60 @ 30MHz, and this tripler need a sine wave to work right.
There is still some work to be done before I can put the beacon back on air. But as they say in broadcasting; Stay tuned, will be right back after….
PCB measures 60x20 mm and parts are SMT
Schematics
Measuring reflection (S11) with the minivna. Return loss is more than 26dB @ 10MHz.
Measuring transmission (S21) with the minivna. 1dB insertion loss @ 10MHz and cout-off at 12MHz.
Have been working on a crowbar circuit for my universal high voltage power supply for some time now.
And here is a early preview of the circuit. This unit is meant to bolt right on top of my 5kV 100uF filter capacitor.
As the picture shows I have cut a air gap into the PCB to strengthen the isolation between high an lo- voltage areas on the card.
Here is the schematics of the circuit. And I must emphasize, this circuit is not fully tested yet!!!
Here is a Hi-Pot tester I have just finished.
Hi-pot tester is good for 11Kv at the terminals and the leakage current is 3uA.
I’m pretty happy with the result.
Testing a Burle 8792 transmitting tube. Leakage is 3uA @ 7Kv
Inside view from the top
Schematics
I’m trowing in a couple of pictures of the FOX DELTA ST2 Antenna Tracking Interface that I have build.
Unit works great, but on the bench for the moment. Antennas ain’t finished yet. 
I’m in the proccess of building a 144Mhz 4×7-Element-Yagi array for EME. ETA not known.
Here are some pictures of my second GPSDO.
This one, like my first GPSDO is based on the G3RUH James Miller desing.
Whats new with this is that I have added a Picaxe controller and a display unit for decoding the GPS NMEA-0183 sentences.
The display show various information decoded of the gps sentences.
But the main reason for building the MKII was that I needed it for controlling my DDS based WSPR Beacon.
GPSDO 10Mhz output drives the DDS and the micro-controller which steers the DDS.
The picaxe gps decoder take care of the keying of the beacon at the start of every tx period.
Ii’l will come back with a separate post regarding details of the wspr beacon.
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