Ralf's Zenith Trans-Oceanic

One of my favorites: a Zenith Trans-Oceanic H-500 with a 5H40 chassis. Chassis' serial number is 2534156.

Doing a inspection of the radio I didn't found a matching revision of the H-500 series. It has not only 5 tubes, an additional socket exists for use with a 50A1 ballast tube in case of line voltages of 130V. I discussed this issue with Padgett and I learned the 50A1 feature was first introduced with the R-520/URR model, the military version of the H-500, and then continued in the L-600. Padgett told me he had heard about bridge models between the versions. And now we have the living example: a H-500 with the 6th socket!

In the manual one page is revised with a sticker telling about the 50A1 socket, and under the sticker on the original page the voltage switch of the C-revision was described. So it is later then the C-revision. Now Padgett described this model as a D-revision, probably from the mid 1953.

The number on the speaker is 49CZ668. Inside the case there is a printing 'May 29th', but the year is not readable. I guess it must be 1953.

Basically the H-500 is designed to operate on 110-125V AC or DC, or to operate with the battery pack. A 220/110V AC/DC adapter was provided for line voltages of 220V to 240V.

Band	Meters	Kilocycles

Standard Broadcast	555M to 188M	540Kc to 1.600Kc
Weather, Marine and SW Broadcast	75M to 38M	4.000Kc to 8.000Kc
Weather, Marine and Amateur	150M to 75M	2.000Kc to 4.000Kc
Short Wave (Morning)	16M	17.500Kc to 18.100Kc
Short Wave (All Day)	19M	14.900Kc to 15.500Kc
Short Wave (Afternoon & Evening)	25M	11.600Kc to 12.000Kc
Short Wave (Afternoon & Evening)	31M	9.400Kc to 9.800Kc

The radio is in a very good condition, works pretty well hooked on a transformer with 115V AC output. As with most of this radios I had to do some restauration on the power supply. The old selen rectifier was gone, some times ago, a diode was already soldered over it. Also a voltage bleeder resistor was already used. Now I've changed all of the power supply capacitors due to some hum problems. This action cancelled really all hum.

I found somebody in UK who is building 230V-to-110V adapters including a fuse to protect the radio. This adapter occupies the same place like the original adapter I've mentioned above. The adapter is build by John R. Beran / Natural Selection Radio Restaurations.