[morzh]

How much is it? $560 / pc? Or special order only?

[RodB]

Dollar$289 On backorder a couple years.

[radiorich]

Hello rob,
I have never seen that value before that is a new one for my 24.6 ufd
Sincerely Richard

[morzh]

Probably a measured value.

[LarryD]

Yeah, it's a Kemet 22uf 450V axial cap, but it measures 24.6 @ 400V on my Sencore capacitor analyzer. Close enough for me.

[RodB]

Larry, what's most important is the leakage. That indicates how well the capacitor holds a charge. If it leaks at all it's on the way to being a resistor. And that sometimes means smoke.

[morzh]

Well, electrolytic caps naturally have higher leakage than the rest of the caps.
This is exactly why, when serializing them, we sometimes have to use those equalizing resistors, to counter the potential differences in leakage currents.

For the aluminum caps it is calculated as a function of some number multiplied by CV and then plus a few microamps.

For instance, the leakage of a 22uF 500V cap, EKXJ501ELL220MK35S, by Chemi-Con is:

After 1 minute
I=0.04CV+100uA, which is 540uA. Half a mA !!!

After 5 minutes
I=0.02CV+25uA, that is 245uA. A quarter of a mA.


So, as long as it is within specs.

[LarryD]

My cap checker checks for leakage and this Kemet cap is testing normal, similar to how the Nichicon and Chemi-Con caps test out. Checked the ESR as well.

[morzh]

Mine is good (Stanford Research) but does not check leakage per se.
It checks the dissipation factor though.

[LarryD]

Waiting for parts order to come in.....

[LarryD]

Parts came in and I have all the capacitors replaced, plus a few resistors that were out of spec. Bad 6J5G tube replaced as well. The only resistor I did not check was the multi-section one. I will have to get back to that one before I put the chassis back in the cabinet.

Meanwhile, I did slowly apply voltage with the variac and brought the radio up and have it playing. Sounds okay, but I have a bit of noise on the lower end of the tuning dial. Not able to clearly bring in the station at 580 on the dial. 670 comes in loud & fairly clear, but 580 has a lot of loudish white noise and is very faint.

It also had a squeal for a little while, but once I re-cleaned and tightened up the socket on the 6K7 the squeal disappeared. I found the source of the squeal by poking around the inside of the chassis with a dry popsicle stick and noticed when I jiggled one of the socket pins that the squeal stopped.

Next I'll check the multi-resistor and make sure that's going to be in spec. The only question I have right now is: What can I do to get rid of the hashy white noise at the lower end of the dial? It's fairly quiet above 900 on the dial.

Larry D.

[MrFixr55]

Hi Larry,

Check by using a similar radio (if you have one) in the same location, connected to the same outlet and using the same antenna. AM is susceptible to noise and our houses are now full of it with all the CFLs, LEDs, Bluetooth and WiFi everything including the fridge and microwave, etc., etc. Google the station call letters and frequency. There is likely a Wikipedia article which states the station location, day and night power, antenna propagation, whether "clear channel", etc.

If you used a 2 wire plug, make sure that connect the ground connection of the chassis to a water pipe ground, as close to the entrance to the house as possible or to a good made ground such as a ground rod separate from the house electrical system, sunk into moist earth.

If you are using a 3 wire power cord, grounding the chassis to the house wiring, consider lifting the ground and using the separate ground described above.

[LarryD]

I'll try out turning everything off after everyone goes to bed. Our plumbing is all plastic. The only grounding rod is used by the house's electrical system. I'll try out a few different things. I do have another radio I could try out as well.

Do you have any idea what the multi-section bias resistor's wattage is? Can't seem to find out what it's supposed to be.

[glyphmon]

Larry,

Based on the part number for Resistor 43 on the schematics for your model, this came up:
https://www.philcoradio.com/phorum/showt...?tid=16971
It's a discussion about a model 38-10, but it's incidentally also part 43 there as well and the same part number.

In there, Mike (Morzh) has recommended a minimum of 3W, but 5W to be completely safe on the 202 ohm segment, while the others could be safely 1W.

Best wishes,
Roy

[radiorich]

Hello Larry,
What I did was install a separate ground rod for grounding my antennas and my antistatic mat on the bench. My older house mostly has two-wire Romex, and only the newer circuits have a ground.

Sincerely Richard