New Tubes for an Old Zenith Universal
 

Put an new power cord on my Zenith Royal G503 Tip Top. This is my first foray into it innards. not much there compared to My Trans-Oceanic 600's. It is going to need to be recapped, the Selenium rectifier is functioning fine but it is scary looking and is getting the heave-ho. The Tubes: except for the 1L6 (got lucky there) all need to be replaced, the 3V4 is marginal. The question is which brand. My favorite tube line is the JAN tubes, Joint Army Navy, which where made to government spec's by whomever got the contract. I don't have such a choice with this Zenith Universal.

I need 2 1U4's, 1 1S5, and a 3V4.

What advice do you have for me.

I purchased tubes I needed form Surplus Sales of Nebraska
http://www.surplussales.com/
They have the largest inventory of vacuum tubes that I know of, and the best prices.

If that is not a shortwave capable model then I'd recommend replacing the 1L6 with one of the more common (non-shortwave capable) equivalents (1R4?) and saving the 1L6 for a transoceanic or similar.

It is a 1R5, and when you are testing and restoring a Trans-Oceanic it is a good idea to use the IR5 while testing. I have a good supply of 1L6's and because the Universals will not have that much use I will leave them in place. In my tube type Trans-Oceanics I have changed out the 50A1 ballast tube with a solid state replacement which protects the 1L6 and gets the most performance out of it. Read about the test of it here: http://www.ppinyot.com/T/50a1.htm

http://www.solidstatetubes.com/uploa...42/5056205.jpg

I now have a similar device that replaces the all but extinct 3TF7 ballast tube in my R390.