[600MRG] " Junk Box Jewel "

[Dave Riley]

Recalling an article in CQ magazine during the mid 50s called " Junk Box 
Jewel ", was just the rig I wanted to build. Unfortunately the small and 
meager junk box had no such parts to scrounge from. The 'jewel' 
consisted of two small aluminum chassis with the power supply built in 
to the bottom small chassis and a 6V6/6L6 oscillator amp in the stacked 
top chassis. I felt lost so kept resorting to ARC-5 and other surplus 
units as a way to stay on the air. The junk pile began to grow at this 
point and I must say that 60 plus years later has grown to at least a 
source of one of anything to draw from as cannibalized 'parts' for 'new' 
home brew projects. At last a decent 'junk pile'...
Edison said something like 'an inventor needs a fire in his belly and a 
good pile of junk' ( sic )...
After several years off air I returned to ham radio and decided to get 
reacquainted with WSPR on the 630 meter experimental band as WD2XSH/17, 
QSL sure via the server...
Two weeks ago this transmit converter appeared from the junk pile which 
translates the IC706 down to 475 khz. So using the 706 as the IF @ 
10.475mhz and a GPS clock output @ 10 mhz. both feeding into the double 
balanced mixer does the heavy mixing...

http://www.radiocom.net/600M/JunkBox.jpg

Start with a surplus external hard drive case as they make a very good 
home for parts, wires, and sub assemblies holding new prototypes...

On the upper right is the double balanced mixer with three bnc 
connectors to/from the outside world.
1. GPS 10 mhz. clock for local oscillator
2. 475 khz output to a low pass filter ( the red/white toroid ) red sma 
lead.
3. Low power from the IC706 @ 10.474200 mhz USB as the other input to 
the mixer ( upper right )

The IF signal enters it's new home and becomes cleansed @ 475khz through 
the red low pass filter toroid, thence to the instrument amp. ( +20dbm 
amp. DC-300 mhz. )
The output of the instrument amp is about 10 milliwatts of clean sine 
wave, the other mixer products being banished away to someplace (?).
The output of the 'volume control' varies the drive to the former novice 
5 watt CW transmitter kit now reworked for use as a continuous duty 1 
watt buffer amp which feeds the Ramsey 'remanufactured' Q-Amp with 
rewound ferite transformers, added 'real heat sinks' and updated IRF fets.
The original mini housing fan makes for silent cooling for the P-P IRFs 
that can pump out 25 watts of clean sine wave @ 475 khz..

This project was fun and full of re-learning... The IC706 was previously 
on 10ghz using the same home brew methods..

As of this week the best DX here is to Hawaii over to Norway and Eastern 
EU, not so bad for 1 watt eirp... ( lousy antenna )

Have fun, ham radio is still a blast!! ( especially when we get old )  
Junk list anyone??

73s from DaveR WD2XSH/17