Resuming the Sparrow

Ok, I don’t know what happened… For some reason, no sparrow progress since Oct last year. Anyway, I am back, and working on the Sparrow again!

I have now finished section 5 of the Sparrow. This is the RX input section including the low pass filter. I have found out that I have been building the transformers wrong. Instead of winding the secondary after the primary, I should have done them together. This way it is much easier to aligne the wires. I didn’t yet mount the optional parts but I think it will be best to mount them at some point. It is, however, a little strange that there is no mention of them anywhere in the manual, not even their value. I think R40 should be 470R since it has similar purpose as R1.

This completes the whole receiver. It is about time to make some more advanced tests than touching some test points. I will either use the FT-817 as a signal source or build some of the signal source kits from Elecraft.

I should also mention that I have mounted the optional parts in section 5, namely D14 and C104. I didn’t mount R40 since I am not sure about the value. Probably 470R…