1956 RCA CTC-5 is ALIVE!

[bigaudioal]

CTC-5 was looking great until it blew the horizontal sweep output fuse tonight and I lost HV. Fuse is a .300 amp 250 volt C type. Assuming it is not a slow blow fuse, correct?

Now I am really gonna leave it be until someone more knowledgable than me can run some key diagnostics to make sure the set is running ok. Anything obvious I should look for that may have caused this?

Figures!!! Just got the convergence all set up!

[bigaudioal]

Another pic

[Electronic M]

Originally Posted by bigaudioal

CTC-5 was looking great until it blew the horizontal sweep output fuse tonight and I lost HV. Fuse is a .300 amp 250 volt C type. Assuming it is not a slow blow fuse, correct?

Now I am really gonna leave it be until someone more knowledgable than me can run some key diagnostics to make sure the set is running ok. Anything obvious I should look for that may have caused this?

Figures!!! Just got the convergence all set up!

Key with any roundy is to adjust the horizontal linearity/efficiency coil for minimum H output cathode current (it will be a dip) using a 0-250mA or 0-500mA meter in series with the cathode. Should be covered in sam's horizontal adjustment procedure.

It is also wise to look at the H osc. waveform on a scope to make sure it is correct, and check the grid drive of the H output tube before the current dip to ensure the tube is being driven properly.

[bigaudioal]

Originally Posted by Electronic M

Key with any roundy is to adjust the horizontal linearity/efficiency coil for minimum H output cathode current (it will be a dip) using a 0-250mA or 0-500mA meter in series with the cathode. Should be covered in sam's horizontal adjustment procedure.

It is also wise to look at the H osc. waveform on a scope to make sure it is correct, and check the grid drive of the H output tube before the current dip to ensure the tube is being driven properly.

Thanks. Nick Williams is going to drop by sometime soon and hopefully help me check all this. I do know where the horizontal linearity/efficiency coil is and this check looks fairly simply. Just set meter to mA's and hook between chassis ground and the exposed top of the horizontal sweep output fuse (after replacing it with new fuse). Then tweak the coil for the minimum mA reading.

[zeno]

Leave fuse out. Amp meter completes the cathode connection.
Usually you also put a cap ( .01 IIRC ) across the meter too.

73 Zeno
LFOD !