67.5 Volt Battery Replacement for Portable Tube Radios

Description

This offering is for an inverter to provide 67.5 Volts for tube type portable radios.
Many antique, vintage, and portable radios built in the 1940s and early 1950s used special 67.5 Volt "B" batteries in addition to a low voltage battery for filaments.
Although you can still buy “B” batteries, these high voltage batteries have problems. They are expensive, costing anywhere from to each, and they don't last long.
Substitute batteries can be built up from common 9 Volt transistor radio batteries.
Unfortunately, the cost of the 9 Volt batteries, assembly effort, and packaging, make such do-it-yourself batteries problematic.
As an alternative, the hand built inverter being offered here uses four cheap AA batteries (about $.50 each) in a package smaller than the original 67.5 Volt battery (Eveready 467, RCA VS016, Burgess XX45, Ray-O-Vac 4367, Philco P67, Batrymax B101, and others).
Four AA alkaline batteries will power a conventional four tube portable radio for approximately 10 to 20 hours.
Inverter input voltage requirements are wide enough to allow use of single use alkaline, carbon/zinc,
rechargeable NiCd, or rechargeable NiMh batteries.
In addition, this inverter has a special design feature that automatically turns off the inverter when the radio is turned off.
There is no need for radio modifications or a separate inverter on/off switch.
The inverter senses the tube load when the tube filaments are active.
So, the four AA batteries can be left in the inverter once it's installed in the radio.
The inverter will be shipped with four fresh AA batteries installed.
The two output leads are terminated in alligator clips.
For the 67.5 Volt output, the red lead is the positive and the black lead the negative.
The alligator clips will allow connection to most radios without modification.
The inverter is smaller than many 67.5 Volt batteries, so often it can be enclosed in an empty battery case to simulate a normal battery.
The photos show several views of an inverter installed in a vintage RCA portable radio (not included in this auction), comparison with a 67.5 Volt battery (also not included in this auction), and a few performance graphs.
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Payment Options: PayPal is preferred. Requests for other payment options will be considered on a case by case basis.
Terms: It will be shipped as described.
If not received that way, return it.
On receipt by the seller the bid/purchase price will be refunded.
No warranty is implied beyond being as described here on receipt by the buyer.
Shipping Options: Shipping and handling is .00 to any location in the lower 48 states.
Other charges for insurance (optional) or shipment to other locations will be per value and weight based shipping rates. Shipment will be within the
U.S.
only, but includes the eBay
US
shipping center using the Global Shipping Program.
Bids: The right to block bids at the discretion of the seller is reserved.