Friday, November 3, 2017

Ideas accomplished

Well, I managed to accomplish the ideas from my test with the 30m W5OLF WSPR VCXO- AXE. The digital readout has been easy actually, a 5 minute job. The digital readout shows the voltage after the L78S10CV regulator which provides a constant 10V when the source is 12V and higher. However, when the battery is providing lower voltage when it gets empty voltage will stay 2V below input. The transmitter only has 1W when voltage is 10V. There was a power/voltage graph in the building instruction but unfortunately cannot find the instruction here anymore. From what I remember is that power/voltage was almost related. So a indication of 10.0V is 1000mW, 8V would be approx 800mW. It is a nice indication from what output to expect. And it looks nice as well.

While testing the new digital readout display I connected the transmitter to my magnetic loop inside the shack again. Look at the signal I have in south-west england at G8ZSG. It would be no problem to make a QSO in digital modes or CW.

Unfortunately the weather doesn't permit me to try the magnetic loop outside. We got a lot of rain these days. However I'm very curious what the difference would be if the magnetic loop is placed in the open air...

A piece of electronic art.....destroyed.....

I had a nice old SWR/Field Strength meter which I bought for a few bucks on a auction. It is almost a pity I use this piece of electronic art as a donor. But it features all the components I need except the 10nF caps which I removed from a old printboard. I used the very simple field strength diagram from KY6R's weblog this time as it seems it is a very sensitive design. The components were soldered together and the whole thing was tested with good result. I build the whole thing into the box with the varicap. It was a little tight but works fine for me.





The only thing I wish to modify is the pickup antenna of the FS meter. The whole thing seems to be having some handeffect. I might attach a plastic knob on the sensivity potmeter as well.

4 comments:

Paul Stam PAØK said...

Hallo Bas, leuke set up. En het werkt ook nog allemaal. 73 Paul PC4T

PE4BAS, Bas said...

Ondertussen ben ik ook al over de grote plas gespot. Dus DX met 1W en een magloop binnenshuis is zeker mogelijk. Maar niet makkelijk en ook niet elke dag te doen. 73, Bas

Hans said...

Hoi Bas, leuk dit project. Je heb het weer mooi gemaakt. Simpel maar het werkt en daar gaat het om. Mijn complimenten!
Wat betreft handeffecten bij de loop, dit kun je oplossen door de assen te verlengen met kunststof pijpjes zodat je hand op afstand blijft. Ik paste het vaak toe op de afstem C van de loop.

PE4BAS, Bas said...

Hallo Hans, als ik de as ga verlengen word het wel een heel kwetsbaar kastje. Ik zet er maar een kunststof knop op dat scheelt tenminste wat. 73, Bas