Philco Seventeener II

[wa2ise]

To get some experience with SMDs, get a hold of a junk board out of a computer, router or BPC TV set. You can unsolder SMDs by using a pair of soldering irons, one at each end of a cap or resistor. Be aware that newer stuff used unleaded solder, which melts at a higher temperature. Sometimes adding some leaded solder helps to get the solder holding the SMD to melt. I've had success with larger SMD resistors (ones about 1/10 inch long)

[Notimetolooz]

I find the concern about SMD parts a little surprising. I've worked professionally with SMD parts for over a decade. Its really not much of a problem unless you are dealing with large IC or very small parts. I regularly worked with resistor and capacitors as small as 0402 size. For something like that you do need a stereo microscope, sharp tweezers and small iron tips. Just melt some solder on one pad, position part with tweezers and remelt the solder blob. The first connection will hold the part while you do the other connections. The small two terminal parts you can actually remove by melting the solder on both pads at the same time by laying the iron against both pads and then pushing the part off the pads. Clean up one pad and put down the replacement. Larger parts will require solder-wicking each connection before removing part.

[Crist Rigott]

I'll have no problem working with the SMD's.

The boards are almost fully designed. Some are just a little taller which won't be a problem. I designed them using 1W resistors, hence the reason they are a little taller.

Parts are on order for them.

I still don't know if 200V will be enough for the 82pf cap in K6. It is connected to the plate (pin 3) of V4, the Sync Separator tube. The schematic shows 70V on pin 3. But then there's a resistor R39 at 150K connected to the 265V supply. The 82pf cap is on the resistor side and plate of V4 of that 265V. I'm not smart enough to be able to figure out what the voltage should be except that it should be at least 70V.

[Crist Rigott]

Another question. The fusistor is 5.6 ohms. I'm going to replace it with a resistor and a separate fuse. The parts list doesn't show what the wattage rating is. I did an Ohm's Law calculation based on 120W and came up with a 5.6 ohm 5.6W resistor. I'm going with a 10W wirewound enamel resistor. Do my calcs seem reasonable and a 10W seem right? I'll go with probably a 2 1/2 amp fuse.