A Larger Equipment Case . . .
. . . with a perfect trap door for a Morse Code Key
I have received the 4 States QRP “Bayou Jumper” and add on “Souper Upper” kits. I also have the QRPGuys EFHW antenna tuner kit and the last piece of the puzzle:
QRPKits Amplified Field Strength Meter
and the schematic – a simple yet effective circuit
We got back from Bend on Monday, so Tuesday night after work I played around with a passive Field Strength metering circuit, and was trying a couple Simpson meters that I have purchased. The passive circuit does drive a DC Microamp meter to about 20 microamps full scale – but that is with a 100 watt rig. With 5 watts the deflection is not enough, and while I could play with the circuit more, I decided on going with the powered and amplified circuit – it will be more accurate and drive the meter better and more consistently. It will be easy to create 3 volts from the 12 volt supply that powers the rig – and also use a meter instead of a LED to show power out.
There is one big meter that I would love to use:
0 – 5 mA Simpson meter (actual meter looks new – photo is crummy)
The powered circuit means all I will have to do is either just use R2 to set the sensitivity of the meter (5 watts will be full scale – or a 5) – and if I need to – I might have to add a resistor in series if this circuit and the meter I use is too sensitive. From my experiments I think one of the meters I have will work just fine. As much as I love the big meter with markings 0 – 5 (just a perfect scale), I expect that I will have to use a smaller meter – there is only so much “real estate” with the boxes that I have to chose from.
This meter might win out over the Simpson because of its size – but it has a nice “period look” to it anyway
KY6R Spy Radio Block Diagram
One of the things that I will have to do is order a new black face plate from Tap Plastics. They will take a sheet of black acrylic and use my direction to drill holes in it. I have a “template” for the Bayou Jumper – which is its face plate – but because I will need to add holes for the FSM Meter and Souper Upper Filter switch and Fine Tune controls – plus the EFHW tuner control – the full circuit has extended the Bayou Jumper to something pretty heavily modified. It is all modular though – and with the old oak case with its nice leather handle and Morse Code Key “cubby hole”, I will have something that looks more “of the period” than the Bayou Jumper kits suggestion to use a wooden carrying case from Hobby Lobby. They are “cute” – but I want something that looks a bit more the part.
Bayou Jumper in a “Hobby Lobby” wooden box – cute but too clean for what I want
If I am really lucky – I will be able to use some of the controls that came with the old test equipment boxes that I have. If not – that’s OK, I have everything I need to make something work and to make it look really great. Because of the extra controls I need a bigger box anyway – and the one’s I have are big enough to accommodate them.
I will use the knobs from the test equipment and old binding posts for the wire antenna – so every detail will be as “oldie worldie” as possible. I have the perfect WWII British Morse Code Key – it has black bakelite and will fit perfectly in the trap door compartment. I won’t mount a key on top of the box – but will use the external “period piece” key instead.
One thing I have which is ultra cool is a set of FT-243 crystal packages that adapt new crystals to the old holder-packages. This means the crystal socket for the Bayou Jumper holds the FT-243 crystals – which means it really will look quite authentic – especially with the old oak equipment case, the old knobs – and who knows – maybe even some of the other parts from these Leeds and Northrup test gear boxes.