Monday, October 14, 2013


     Mounted and partially wired the volume control, wired up more of the 6L6 RF amp last night:
     Closeup of the tube wiring.  Still have the power supply to wire up.
     Inventorying my end-link transmitter coils from Bud and Barker & Williamson, 160, 80, 20, 10 and 5 meters I have in good shape.  For 40m, I repaired a coil earlier.have nothing marked and I'll just have to see if any of the unmarked ones will hit the band.  If not, I guess I'll be making one.  (My earlier notions were incorrect.  For some reason, I thought I'd repaired an 80m coil.)

Thursday, October 10, 2013


     I made some impressive-looking progress this afternoon and stopped to photograph it because it's an example of a technique not everyone knows about: prewiring.
Photo is very large if you click on it
     There are a number of controls and jacks mounted on the front panel and it's a pretty tight fit.  Rather than mount them and try to get into a small space with needlenose pliers, soldering iron and solder, I wired up the most challenging (a multi-contact jack and a toggle switch) on the bench, and connected the input transformer to the microphone jack before installing it.

     This results in quite a few wires cut a little longer than necessary.  Yes, there will be some waste and yes, they sell that stuff by the foot, but how much does frustration cost?  By color-coding them, it it's easier to sort them out -- blue is plate return, red is B+, gray is cathode and switched ground, and black is ground, which are (mostly) old-time standard colors.

     The audio level control remains to be wired up and put in.  It mounts right in front of the rectifier tube, so lead dress will be important.  You can see the shielded lead from the mic transformer headed over to the empty hole in the front panel; another shielded wire will return from the control to the grid of the modulator tube.

     I had a bad moment when I realized I don't own a 1/2" Spintite driver to tighten the nuts of the 1/4" jacks.  But I do have a perfectly good modern Klein nutdriver that size.

     My workbench is a little chaotic at present.
     As usual, tools have outstripped tool storage and projects have grown to take up the available space.  There's everything from the remains of an old soldering-iron control box and a balanced-line transmit-receive switch that didn't work out (not enough power supply for the relay!) to my QSL-40 transmitter, a box of pegboard hooks and big piece of un-etched PC board.  Somewhere over on the left is a jack box for the CW transmitters (half of them have the key jack on the back, some have heathen connectors that decent folk would never use instead of proper 1/4" two-circuit jacks) and a narrow audio filter.

Tuesday, October 8, 2013


     I finally downloaded the manual for my (obsolete) 666-R VOM -- Triplett's product support is quite good! -- and loaded batteries for the ohmmeter function (2 AAs and a C).  This puts one more meter on my bench for the ongoing Stancor 10P transmitter project, which has been considerably slowed due to lack of time and energy.  The 666-R is the smaller version of their 630; only 1000 Ohms per Volt but a good, solid meter, well worth owning.  It has the same single range control setup as the larger meter:
     The meter leads are, as you might expect, much newer.  I love old meters but old insulation can ruin your day.  (I'm rebuilding a set with super-sharp phonograph-needle tips, something very useful that you absolutely cannot find today.  Mind you, replacement needles for your Victrola are out there, but the once-common test probes with tiny pin-vise chucks for them are no more, probably because of some kind of product liability issue.  Fluke does make some very sharp add-on probe tips, at least.)

    For the Stancor 10P transmitter, I'm bidding on some more plug-in coils of the 50 Watt, end-linked variety that, if I win them, will help a lot with being able to put it on the 80 and 160 Meter bands.  Finding the end-linked ones has been slow; I have coils for 20, 10 and 5 (!) Meters in decent shape, fixed one for 40 Meters that wasn't, and have a couple more in need of much repair.
     I'm still hoping to put them back into useful shape.  It's slow and fiddly work.