|
|
|
At a first glance, this is yet another homebrew radio equipment.
National "Velvet" Vernier Dial is mounted prominently, which was quite popular among homebrewers.
Controls are neatly mounted.
From the indication of "PLATE" and "LOADING", you would guess this is a vacuum tube transmitter.
"BAND-SWITCH" tells you that it covers multiple bands.
"MIC" jack is a proof of phone transmitter.
"VOLUME" and "PITCH" further states it also contains a receiver;
so your best guess would be a vacuum tube HF SSB transceiver.
Note that the panel carries "PHONE" jack.
|
|
|
|
|
Viewing from top, you see Print Circuit Boards instead of a row of vacuum tubes.
And if you are already familiar with the interior of SB-34, you might have the idea.
This might be a repackaged SB-34;
perhaps someone burnt out the power transformer of his SB-34,
and repackaged it into homebrew style so that he could use his older power transformer instead of paying expensive servicing fee.
But when you starts comparing it to SB-34,
you will discover that the PCBs of this radio are not the same, although quite resembles.
As a matter of fact the circuit of this radio is not that of SB-34, nor of SB-33.
This MUST BE A PROTOTYPE OF SB-34!!
|
|
|
|
|
The bottom view shows very high skilled finish, especially its wiring work.
You may want to compare the PCB pattern - quite resembles to SB-34, but not the same.
Four HF oscillator crystals are there, and the RF slug rack tuning system is visible.
|
|
|
|
|
Close up of the slug rack tuning mechanism. Again showing the high skill of the builder.
In the mass production model of SB-34, this slug rack with band switching rotaly switch is driven from a Geneva Mechanism,
which also drives the tuning capacitor.
In this set the tuning cap is driven by an independent knob.
|
|
|
|
|
This radio has no indication of a manufacture, model number or name, date or serial number.
The only clue of the model name in this set is shown here; it clearly states "SB-34".
John is trying to get this radio working.
His difficultiy is that the actual circuit does not match to SB-34 or SB-33;
it means there were many modifications and improvements from this prototype.
I hope someday John completes his venture and QRV with it.
He surely owns a history!
|
|