[hpsdr] DIYers - OZY board finished

[H. Gruchow]

Hi all
after my 'burning' experience with reflowing OZY I totally hand-soldered the second OZY 
board and finished it the day before yesterday. I am still missing one part: the 3.3 Volt 
LD1117 regulator. I had ordered them by mistake in D-Pack instead of SOT223. Now I have to 
wait a couple of more days for the first light to appear.
I have a bunch of 3.3 Volt LDO regulators TS2940 (available from Mouser and from my 
favorite european parts supplier) in my parts box but since the LD types have such a funny 
and odd pin-out these do not fit.
Maybe the HPSDR designers should consider the TS regulators in the future. Their pin-out 
is more 'natural' : input - ground - output , which gives a nice, compact and very 
straight-forward layout together with the two required capacitors. And they are cheaper 
than the LD types and can bear 1A instead of 0.8A for LD. I do not know which chip 
designer designed the LDs with ground-out-in but that must have been somebody thinking 
around corners (or maybe a left-hander; my whole family is left-handed, so I know how they 
think :-) ).

JANUS is half finished so far. Takes a couple of more hours to get everything soldered 
down. By the way, I have a few LT1128 OpAmps left over. If somebody is interested please 
email me (EU DIYers only).

Over the weekend I will post some pictures and also will start to document the making of 
JANUS as part two of the JANUS documentation. Part 1 will be updated to reflect the 
production schematic.

So a lot to do.

OZY reflow
I heated up my ruined OZY board once again in order to get the two parts off the board. 
With this I also tested the temperature accuracy of the thermocouple. The solder according 
to the datasheet gets liquid at 179 degrees C. When the thermocouple showed 175 degrees I 
tried to lift the parts off the board. They were still fixed. At 185 degrees I tried again 
and could lift them. The solder had liquefied. I think that is pretty accurate for an 
amateur reflow oven. So overheating of the board can be excluded from the list of possible 
reasons and also excessive infrared emission because the two heaters are covered and do 
not directly radiate IR to the board.

73
Horst
DL6KBF