When I worked in aerospace a common saying often heard was "good enough" for government work. I wonder on the 80th anniversary of D Day if those designing the invasion said, "good enough".
Today's subject covers homebrew rigs that are good enough for our individual purposes but when viewed by the masses are seen as inadequate. I get this all of the time.
One of my rigs that got a lot of that grief was my design of the KWM-4 which is a dual conversion multi-band rig that does both SSB and CW and most importantly uses a Collins Mechanical filter in the 2nd IF.
Where it was not good enough, for some, was that 30M was omitted -- for cause. The 1st IF is at 10.7 MHz and for me that was too close to the 30M band and therefore omitted. The 10.7 MHz choice afforded me hardware such as commercial narrow band FM Crystal Filters and a stock crystal frequency of 10.245MHz when up converted with the 455khz 2nd IF put the signal in the 10.7 MHz passband of the FM filter. Easy decision for me: redesign the whole radio for a different 1st IF and build a lot more hardware or simply omit 30M.
Another not good enough is that 98% of my designs do not cover CW operation. I have often said that designing a really great CW transceiver is more complex than a SSB rig. The how come this doesn't do CW comment, I often get.
One issue will be the bitching that the SSB Filter is too wide. The prior two photos show a SCAF Filter (Switched Capacitor Audio Filter) which could be added following a SSB filter to process the audio so that you in effect have a very narrow audio range of signals to copy.
I have not delved into the innards of a SCAF filter but do know they work. Ten Tec in the Triton series had a very effective op-amp audio filter that enabled using a wider SSB filter that produced for TT a highly effective CW transceiver.
One blog reader emailed me that he designed and built a synthesized rig that he shared with his local ham club at a Show and Tell. Yes, when he popped the hood: Well, why did you do this or gee it would really be better if it had this functionality or feature. We must forgive the club as the locale is on the right coast (the Home of Tony Soprano) and in addition to having funny accents that is just their nature.
So, good enough, often starts with a requirements list of the designer especially where this is a personal use project and not for a commercial product offering. Not having CW in one of my transceiver projects is by design. But if you want CW you will have to do the design -- so don't bitch a me.
We should simply appreciate those who design and build their own radios and I often suspect these "not good enough people" are totally incapable of pulling off a project like that and just bitch (envy).
The Pipsqueak above might have some potential as a CW Transceiver with various circuit changes and the addition of a SCAF filter.
Keep on homebrewing.
73's
Pete N6QW
