[Late yesterday afternoon a package showed up from Home Depot. I hardly ever order anything from Home Depot since the store is only 2 miles from my QTH. I checked to see if it was mis-delivered but it had my name on it. Surprise! It was a bottle of Krud Kutter and I have no idea who sent it to me. But a Big Thank You!]
This is a question often asked as if there is some exactly right and only way to do it. Well, surprise there is no singular answer. No matter what way is chosen the care with which it is done, and the observance of good practices are the keys to success.
The big orangutang in the tent is the use of through hole versus surface mount components. The final test is: does the same circuit schematic provide the same performance level with either type of component. In 99% of the cases there will be no difference. The other 1% may cover issues of shielding, compactness and heat transfer.
So, it gets down to the comfortable shoe's response. Going on a hike with a brand-new pair of boots risks blisters while the old reliable pair of boots just keep on walking. It is a comfort zone thing. Those of us with FFS have a hard time holding on to or maneuvering those teeny tiny parts.
Most of the time SMD needs a circuit board whereas Ugly or Manhattan requires nothing more than some pads and superglue. We are always on the quest of "get er done" and that seems easier using through hole and some ugly pads. The sophisticated name is "Rapid Prototyping".
The basic tenet is that it does not have to look good to work well. There is another factor here in that most of the time homebrewing a rig is an evolving process where circuits are tuned and tweaked many times before a final configuration is achieved. Harder to do with SMD as soldering/resoldering can lead to destroyed parts.
Let's face it, SMD really shines on a production line where parts are installed using pick and place manipulators. Manual installation of SMD parts on a board is more Black art than a science. However, the photo above suggests that SMD can work well for home brew projects, and it even appears the circuit board was made using a Dremel tool or a CNC with a dull engraving bit.
The other piece is cost. More and More through hole parts are being shifted to Surface Mount. SMD parts are surprisingly cheap and as less through hole parts are being made the costs increase accordingly. Back to our comfy boots example. New heels and soles on our old boots may approach the cost of a new pair of boots. But with the repairs the old boots are the choice as they are broken in and no blisters. But that is a conscious decision made by the homebrewer
Earlier I mentioned the execution of process, thus with through hole and SMD you still need proper solder joints, circuit layouts that avoid unwanted feedback, and always with an eye toward serviceability. These apply in all cases.
On the record, I use both through hole and SMD parts. But I also design my circuit boards that are cut on my CNC. The boards I design are more universal in nature using a modular approach. If I want an audio amp, I pick a place on a PCB, call up an audio amp design and push the start button. No pad glue downs, as I invested the time in the module designs. Same thing for an IF Module or bilateral amp stage. Pick a place and mill away.
The above photo shows the Mic Amp, PD/BM, IF Module, Rx Tx Mixer and BPF. All are individual modules on the CNC ... Pick a place and mill. The board contains both through hole and SMD (ADE-1's).
So, my way is not THE singular way, and it all gets down to your comfort zone.
Them that know can make things go!
73's
Pete N6QW