The box by the way is bought at IKEA. I think it was 7 different boxes in one set and quite cheap. Next test equipment in the blog will use one from that set too.
Monday, November 22, 2010
Simple signal generator
With a little bit of inspiration from the blog of M0XPD I have built a simple signal generator. The original design is from NorCal QRP club and can be found here. I´m able to create a S1 or S9 signal (more about the s level here) that I can listen to if I´m going to test a receiver. I can change between 4 different crystals/frequencies. As there is no low pass filtering in the circuit there will also be harmonics. Here is two pictures and you can see that it´s been a while since I built it but haven´t documented it until now.
The box by the way is bought at IKEA. I think it was 7 different boxes in one set and quite cheap. Next test equipment in the blog will use one from that set too.
The box by the way is bought at IKEA. I think it was 7 different boxes in one set and quite cheap. Next test equipment in the blog will use one from that set too.
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Hello Erik,
ReplyDeleteThese IKEA boxes are great. I used old metal sigar boxes myself.
I studied the NorCal signal generator. It seams to my that it is an excellent design.
The signal is picked up over a resistor with a low value, so it provides a very low voltage.
The output voltage is 50 microvolt, which is S9.
The two attenuators give 20 dB and 14 dB. So the signal is 34 dB lower. This is 1 microvolt.
I think this is about S3. (in stead of S1)
Thank you for sharing this great design.
73, Bert PA1B
Hi Bert,
ReplyDeleteThanks for the comments. M0XPD commented on this so I did 48 dB pad.
Yes, the IKEA boxes are nice. I think the one I used here is similar to the famous Altoids that I read about. but I do not like to eat mints. :-)
Eric