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Is there any way of knowing whether a R4-B mains transformer is designed for 60Hz or 50Hz ? I got mine from a German radio-amateur decades ago... It has the IC audio amp. Michael 2E0IHW

Probably because line voltage values get kicked around all over the place. I still see 110V quoted although I am not sure it was ever a standard voltage. People just make it up. -- Richard Knoppow Los

Shawn, I have an excellent T-4XB face plate so if you're interested, email me offline/private reply and I'll send you a flatbed scan of it so you can see it close up. There are a few minor scratches

Another, less expensive solution, would be to use a 20A, 10V transformer off the AC line, and hook the secondary in a BUCK fashion to lower the 120-125 volts to around 110VAC. There would be less

For older gear, I use a Variac device together with a 6-recepticle toroidal isolation transformer and adjust line voltage that produces 6.3 VAC and/or 12.6 VAC measured at the tube socket heater pins.

I don't know about receiving tubes, but some high power transmitting tubes can see a dramatic reduction in life expectancy if the filament voltage gets too far outside the mfg recommendation. My 120

I note that in that other well-known (and heavy) brand of receivers/ transceivers etc made in a neighbouring state, it states the power requirement (in manuals to 1975), the line voltage needs to be

Bill and all Yes, I agree - even on my 2B it is 120/240. It was on an R4C I measured the filament voltage of 7.0 one evening. Now their mains transformer may have been originally designed for more

Jim, I just did the same thing. GMTA... So all of the 4 Line was originally designed for 120/240 VAC power @ 50 - 60 Hz. I now have a variac (since I acquired an S Line, which is an older design and

It is rare to find a knob bushing that has NOT deteriorated in these radios. 73 -Jim NU0C "jerry-KF6VB" <jerry@...> wrote:

Just for fun I did a deep dive and pulled up the R4 manual. There it is in glorious black and white: 120/240v. I wonder where this idea that these radios need 115 or even 110v to be happy comes from?

Bill In the UK, where the mains voltage is usually 245 in the evenings, and filament voltage is around 7.0. I use a simple transformer as an autotransformer taking out the 230 or 220 tapping for old

Bill: I will add my $.03 Cdn to this discussion as well. I run (most) of my Drake B and C-lines off Variacs set for 110 VAC. Doing so reduces heat for sure but also output power is lower and as these

Continuing the Variac thread is a slightly different direction ... has anyone measured the AC current draw of an AC-4 (wired for 120VAC) with the attached T4-any running key down? I've never plugged

When all else fails read the manual. The R-4B is specified to run on 120/240 VAC 50/60 Hz with 60 Watts of power consumption. Sent: Friday, November 24, 2023 10:40 AM To: [email protected]

Bill: You have opened up a very large door here. If the radio (this is a BIG if) was designed when the standard voltage was 115V (by law and practice) , then the radio was DESIGNED to be used at that

Bill, When running vintage gear my philosophy is to use a variac, and line conditioner, to keep things around 110 vac. ?Yes, slightly less heat and maybe a little longer lifespan for the filaments.

The TR7/TR5 use a different diameter bushing from the C Line but the same thing can happen there. My first TR7 actually had the opposite problem: the bushing had turned into a gooey, mushy coupling.

Please, is there any advantage to running the R4B receiver on a VARAC for 115Volts?? Maybe less heat I'm thinking... Thanks, Bill N3WM | | Virus-free.www.avg.com |

*** I think that's happening on my TR7. The bushing is hard as a rock. I didn't know it was supposed to be soft :). With a working digital display, it's not THAT big a deal, but still... Sounds like