Monday, November 26, 2012

Random projects II


Between old projects getting finished, a lot more left behind, even more get in the horizon...

...I finished (for now) the AD8307 power meter:

 


 it was rewired in the inside and placed the input signal on the front. With the switch on this position it indicates the internal battery voltage, 9V, still good.

I also placed a rear input for the companion DVM:



There's also the option of using the front panel plug (on the DVM):



Get back to the midle picture... notice the DC motor and the IR slot sensor, had this recovered from a cassete player and a scanner and will proably be used in a NBTV mechanical receiver project I stunbled upon this week...


And when you don't have plugs for 9V bateries, just grab a used one and recover the top, easy:



Not all 9V batteries are equal but you can recover the plug from all of them.

Here's an idea for a measuring grab plug



It works but I have to get a stronger clip...

Some time ago I decided I would only buy new components when stock is empty or can't be recovered from old boards, truth is: I can't remember last time I bought components....hum...it was 2 days ago: 1N5711 diodes, had none and found none in the pile of old rf boards. It takes some time searching and recovering but no money is spent and you can always say: it was junk before, now it's a transceiver :)

Have a nice week!

2 comments:

Eric Söderman said...

Hi Ricardo.

I always like your posts. Keep them coming. My blog is very quiet... I just moved to a new place and now have plenty of space (but not for antennas...) and I will eventually update the blog.

Is your power meter based on the schematics from ve7bpo? I have started to build that one among other projects.

73 de Eric SA5BKE

Ricardo - CT2GQV said...

Hello Eric,

Thank you for the nice words.

The power meter is based on mixed design, I used the front end from EMRFD book with compensation input network that should be good to 500Mhz (not tested yet) and the metering part from here: http://www.qrp.pops.net/RF-workbench-5.asp except I had to change R1 and R2 to reflect my 100uA meter (instead of the original circuit one of 200uA).
I didn't placed the 50 Ohm load inline with the original circuit but use an external one as you can see in one of the pictures (small bnc load).

73 de Ricardo - CT2GQV