Dumont RA113 "Burlingame" restoration

[bandersen]

I went ahead and removed the focus coil which took care of the focus issues. Occasionally, I get a little tearing but it's certainly watchable.
I can't push the yoke all the way into the CRT bell though so it's not filling the screen.


Now as for sound I switched, to using a BT modulator set to channel 5 for an RF source and finally got some good strong sound.
Only problem is that it was miles off from the video. So much so that the screen is blank when I have sound. I tried yet another brand of modulator with similar results.

So much as I'd like to avoid it, I'm going to attempt an alignment - at least on the sound. The alignment instructions in the Dumont and Rider service info and rather complex and involve clipping pins off tubes!

Perhaps the Sams alignment procedure is a bit easier. Does anyone have a scan ?

[Kamakiri]

Forgive the format, but here they are

[old_coot88]

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[bigaudioal]

I have a PDF of the SAMS for the RA113. Can email to you.

[wa2ise]

Originally Posted by bandersen

I went ahead and removed the focus coil which took care of the focus issues.

I'd keep the focus coil if it's being used as a power supply choke. Add extending wires to the coil and mount it at some distant point (away from the CRT) in the cabinet, maybe near the bottom back. So it's available if you or a subsequent owner wants to use it on another CRT.

Originally Posted by bandersen

Now as for sound I switched, to using a BT modulator set to channel 5 for an RF source and finally got some good strong sound.
Only problem is that it was miles off from the video. ...

So much as I'd like to avoid it, I'm going to attempt an alignment - at least on the sound.

Is this a set with an independent sound IF, and not an intercarrier set? You might be able to "walk" the sound IF alignment to the frequency needed to get good sound when a good picture is tuned in. Note the direction you need to leave good sound towards a good picture, and put it back to good sound, and adjust it again back to the direction for good picture, but not completely losing the sound, and tweak the sound IF trimmers to get good sound. Repeat until you are where the good picture is tuned. Then adjust the ratio detector or such to get the DC bias is correct.

[bandersen]

I meant I just removed it from the neck of the CRT - it's still connected electrically. It's not used as a choke though. They have two dedicated chokes mounted under the chassis for the power supply.

Yes, it's split carrier sound. I'm going to jump right the sound alignment portion. If that doesn't work out, I'll start at the beginning.