Categories
Ham Radio

project vs design

[Yesterday: 6? miles]

I’ve been working on various radio projects recently. I sometimes have a hard time finding the itch that I am trying to scratch.

I have the nixie clock all laid out, and that appears to work just fine.  I think I have a solution for the switch-bounce when setting the clock to the right time.  I have put it on the shelf for a bit because I’m not sure a time clock is really what I want.  I wanted to have something which would display UTC so that I would have it when I go to write down radio contacts in my log.  (I do a lot of my operating in the early AM hours and usually by low light, so a lighted clock would be a good thing.)  A further problem is that I need the date as well as the time.  So, the nixie clock solves the time need but not the date need.  I’m still using my goofy radio-clock which has a lighted display when I push the button.. and has the very aggravating DST adjustment problem which has messed me up twice a year for as long as I’ve owned the thing.    So the nixie clock is on the shelf until I figure out what I want.

I have built two signal sources recently, the one based on an AD9850 module and the other on the Si5351A.  I messed around with input ideas to control frequency changing and I have more to do in that area.

I’ve been thinking that I want to build a receiver, maybe an R2 or even an R1.  But I’m not sure what my goal is:  get on bands that I don’t currently have?

Right now I have the headphones plugged into a Hi-Per-Mite audio amp/filter which is lashed to a diode mixer which I yanked out of a VHF radio.  The other side of the mixer is being fed by the Si5351A and the RF connection is to my antenna tuner.  I hear signals on 40 meters.  No volume control, no RF gain, no nothing.  I just tune around.

But then we get into the difficult parts: image rejection, filtering, amplification, user controls, T/R switching.

Frequently with my projects I have two problems:  1 – I don’t have a goal and 2 – I get a ‘deer-in-the-headlights’ freeze trying to figure out what to start first.

I think that is why I enjoy moderately difficult fix-it type projects. I assume that the thing I am fixing had a designer and a design and I don’t have to worry about comparing it with other designs or making design decisions.  I just find the part that is broken and fix it.  I currently have a 47″ LCD TV in the guest room with the back cover off.  One of the circuit boards has a burned trace and a couple of missing components.  I’ve ordered the components and I’m think I can get it working again.  That would be gratifying.  But don’t ask me to design a 47″ LCD TV, that would make my head hurt.