Emerson 1146D Fusible Resistor

[Doug66]

Does anyone have the Sams for an Emerson TV Model 1146D? It's either 298 or 299 Folder 4. All I need is the value and wattage of the fusible resistor connecting to the selenium rectifier.
Thanks in Advance
Doug

[WISCOJIM]

5 ohm, 5 watt.

[dieseljeep]

Originally Posted by Doug66

Does anyone have the Sams for an Emerson TV Model 1146D? It's either 298 or 299 Folder 4. All I need is the value and wattage of the fusible resistor connecting to the selenium rectifier.
Thanks in Advance
Doug

Way back in the day, I used to carry 5.6 and 7.5 fusible resistors in the caddy. Most of them plugged in.
The set must be one of those 14" AC-DC jobs.
I need a 14HP4 for one. A 14QP4 will work, as well.

[zeno]

Its 5 ohm 5 watts. Use a 5.6 ohm its the common value.
Be sure its FUSABLE.

73 Zeno

[Findm-Keepm]

http://www.talonix.com/shop/category.aspx?catid=214

Odd that the Sams shows a PW7-5, a 7-watt resistor made by IRC. Over-rated, and not fusible. Another example of how following the Sams for parts replacement could be a bad thing.

[wa2ise]

Originally Posted by zeno

...
Be sure its FUSABLE.

Or use an inline fuse holder and fuse in series with it.

[Doug66]

Thanks for alll the input to this. I had recapped the set and negelected to replace the resistor.

[Doug66]

Ok, I had to replace the fusible resistor, rectifier, and fuse, but the set is playing again. I have one issue, and it's not one I have encountered before. There is some horizontal pulling in the picture, but it starts at the bottom of the screen, moves upwards, then repeats. I've encountered barkhausen oscillation before, but this is a horizontal line. I have replaced the damper tube and swapped the 6SN7 sync amp and horiz AFC tubes which didn't change anything.

In the pic, the issue is at the lady's head. If someone can give me an idea of the offending circuit, I can know where to start troubleshooting.

Thanks
Doug

[Findm-Keepm]

Open input filter? A bad B+ filter will give either a 60Hz or 120Hz "crawling line" in the picture. Any accompanying buzz in the sound??

It could also be AGC action, see if the AGC control has any effect.

If you have a scope, check out the B+ ripple - but be sure your set is on an isolation transformer and that your scope and probe are capable of measuring ~300V. B+ ripple is dead giveaway to an open filter/smoothing capacitor.

Cheers,

[Doug66]

First, thanks to Steve McVoy and Tom Albrecht for scanning the Sams to the ETF for me.

2nd, this is a portable AC/DC set, and it does not have an AGC control, but does have a 5U8 AGC rectifier.

I've replaced all filter capacitors. Now on the fusible resistor: it's supposed to be a 5 ohm 5W. All I had was a 10ohm 5W, but my source voltages are fine.

I don't have a scope yet. Was going to get one from a retired TV repairman, but the deal fell thru. Here are the circuits that were mentioned. I'll check voltages on the 5U8 next.

[zeno]

A line running through the pix is almost always a
bad filter cap. Usually there is also a hum. One line
is 60 hz, 2 lines are 120 hz. You need a full wave power
supply to give 2 lines.
Other thing is rare. A tube with H-K leakage.
Third thing is interference from another piece of gear.
Check your work then try "jumping" or "bridging" the
electrolytics. More on that if you need it.

73 Zeno

[zeno]

Originally Posted by wa2ise

Or use an inline fuse holder and fuse in series with it.

That will work. A caution on fusables. At an RCA seminar a few
complained that the fusable always opened & not the fuse. TRUE !
They said its because the fusable protected the fuse. TRUE !
Bottom line is when you turn on a set there is a very heavy
current draw to charge up the filter cans. The fusable limits
that & lets the caps charge slowly. If it wasnt there the fuse
would soon fail. It also acts as a fuse, I have only seen them open
with a shorted rectifier or for NO reason, just age. Sets with
them rarely blew fuses !
Last thing is its important on solid state sets with kick-start
circuits. They depend on the slow & proppor rise of the B+ often.

73 Zeno

[Doug66]

One question on the electrolytics. C1A and C2A called for 250uf. All I had were 220uf, so I used them. Could that be causing the problem? If so, I'll parallel a 33uf with each before I start bridging new filter caps in.

Also, on the 5U8 AGC rectifier. Pin 1 should be -.9V. I have -5.97V. Pin 9 Sb -.3V. I have -4.27V. I did replace R30 and R31 coming off pin 1. I had replaced C37 when I did the initial recap.

[old_coot88]

We referred to those fusibles and other large sand coated resistors as 'gravel gerties'. ('Gravel Gertie' being a character in the Dick Tracy comic strip.)

[Findm-Keepm]

Originally Posted by zeno

That will work. A caution on fusables. At an RCA seminar a few
complained that the fusable always opened & not the fuse. TRUE !
They said its because the fusable protected the fuse. TRUE !
Bottom line is when you turn on a set there is a very heavy
current draw to charge up the filter cans. The fusable limits
that & lets the caps charge slowly. If it wasnt there the fuse
would soon fail. It also acts as a fuse, I have only seen them open
with a shorted rectifier or for NO reason, just age. Sets with
them rarely blew fuses !
Last thing is its important on solid state sets with kick-start
circuits. They depend on the slow & proppor rise of the B+ often.

73 Zeno

Zeno,

Remember the Surgistors? The resistor that heated up and closed a bimetallic strip that carried the current? Workman and GC had replacements - I still have a couple, and may add one to my Setchell Carlson.

As to fusibles - Workman had several types - the heavy duty white one, the pink ones in 4.7, 5.6 and 7.5 ohms, and a square cement version called "FUZIT" that they sold in packs of 5. Philcos, RCAs and Sears sets I remember were the fusible killers - always opening up. RCA had one that was soldered to a little phenolic strip, and they dipped the whole thing in varnish. You could tell one had failed - there were flakes of varnish around the resistor.

Nowadays, it's smart to add a CL60/80 NTC in series with the line. Folks think it's something new, but surge/fusible resistors have been used for years, i tell 'em.