I would use 1,000 ohms @ 10 watts for each resistor. Line voltages are higher today and don't think you will be able to get a Zenith replacement.
You could look through PTOP list. They have parts for older radios.
http://www.oldradioparts.com/2a29fl.txt
Norm
:I am in need of a two section candohm for a model H500 Zenith transoceanic. This is a two section resistor, 950 ohms each, used in the power supply. Does any one know if the original part is available? If not, want is the wattage rating of this item?
Have you replaced electrolytic filter caps? Selenium rectifier? Over time electrolytic filter caps dry out and selenium rectifiers have increased voltage drop.
These resistors will heat up as they dissipate several watts. Usually they are bad only when open. These resistors are wire wound and shouldn't change value.
These radios will stop operating if the oscillator tube has low filament voltage.
Norm
:::Hi Bob
:::
::: I would use 1,000 ohms @ 10 watts for each resistor. Line voltages are higher today and don't think you will be able to get a Zenith replacement.
:::
::: You could look through PTOP list. They have parts for older radios.
:::
:::http://www.oldradioparts.com/2a29fl.txt Thanks Norm.....This is a wonderful radio, but as the resistors heat up, they change value causing a slight drop in fil. voltage and it shuts down.
:::
:::Norm
::::I am in need of a two section candohm for a model H500 Zenith transoceanic. This is a two section resistor, 950 ohms each, used in the power supply. Does any one know if the original part is available? If not, want is the wattage rating of this item?
I've had problems with this very resistor too. Total resistance should be about 1900 ohms [950 x 2] give or take 10% or so. This is the 3 terminal power resistor riveted to the chassis on the H500. I've never seen it on a 600 series.
It should read more than 580 ohms. When I measure mine, sometimes I get 1900 or so ohms, sometimes it measures open. It depends in part how firmly I press my ohmeter leads.
When this resistor goes, it often becomes intermittent - thus, it works out of cabinet, but not in cabinet. Was this radio recently shipped, or otherwise subjected to vibration, impact or whatever? Mine suffered from a loose chassis from Arizona to PEI, and the resultant banging from the loose chassis and the "tender loving care" [extreme sarcasm here] of UPS [the cardboard box was a mess] killed this resistor.
I believe it was Norm who suggested two 1000 ohm 10 watt wire-wound resistors. That's just what I did. Its so crowded under there that you may have to drill out the rivets and install two small terminal strips - AES has some "verticle" ones that work great for this. Keep a vacuum nozzle right by the drilling site and the vacuum running while you drill.
My H500 now works fine with the new resistors. Unfortunately, a lot of otherwise knowledgeable folks confuse these with the sand resistor - not the same thing at all folks, as the sand resistor is not partly encased in metal and riveted to the chassis.
I suspect this resistor would last forever but for some trauma - be it vibration, extreme cold, etc.
Phil R.
PEI Canada
Hi Bob
::Let me try this again...the message didn't get transferred....The total resistance is running about 580 ohms to high total thru both sections. Have not change caps. Radio is quite when working. Works out of case guits in the case....Oh glory...
:: Have you replaced electrolytic filter caps? Selenium rectifier? Over time electrolytic filter caps dry out and selenium rectifiers have increased voltage drop.
::
:: These resistors will heat up as they dissipate several watts. Usually they are bad only when open. These resistors are wire wound and shouldn't change value.
::
:: These radios will stop operating if the oscillator tube has low filament voltage.
::
::Norm
::
:::::Hi Bob
:::::
::::: I would use 1,000 ohms @ 10 watts for each resistor. Line voltages are higher today and don't think you will be able to get a Zenith replacement.
:::::
::::: You could look through PTOP list. They have parts for older radios.
:::::
:::::http://www.oldradioparts.com/2a29fl.txt Thanks Norm.....This is a wonderful radio, but as the resistors heat up, they change value causing a slight drop in fil. voltage and it shuts down.
:::::
:::::Norm
::::::I am in need of a two section candohm for a model H500 Zenith transoceanic. This is a two section resistor, 950 ohms each, used in the power supply. Does any one know if the original part is available? If not, want is the wattage rating of this item?