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 Post subject: No sensitivity on SW on Hallicrafters S-119 -- FIXED!!
PostPosted: Jan Fri 27, 2012 12:01 am 
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I picked up a Hallicrafters S-119 Sky Buddy II to fix up for my grandson, but I haven't been able to figure out why it's not picking up much on SW. I can pick up just a couple stations on each SW band with the volume cranked up. BC band works fine. Here's what I've done so far:

1. Replaced the electrolytic caps
2. Replaced bad 6CM8 tube, and checked the other two
3. Cleaned switches

Voltages are off. Below is a voltage chart. The first set of voltages are the expected voltages as per the owners manual, and the second set are the voltages I measured. Voltages were measured from the chassis, tuner set to band 3, volume at minium as per the manual. A schematic is also posted below.

Any suggestions on where to start?
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Voltage chart.jpg
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Image :D

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Last edited by Ed Morris on Jan Mon 30, 2012 6:27 pm, edited 3 times in total.

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 Post subject: Re: No sensitivity on SW on Hallicrafters S-119
PostPosted: Jan Fri 27, 2012 1:02 am 
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It looks like the B+ is low. Perhaps the selenium rectifier (CR-1) is weak. Replace it with a 1N4007 and see if the voltages come up to the correct values.

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 Post subject: Re: No sensitivity on SW on Hallicrafters S-119
PostPosted: Jan Fri 27, 2012 3:38 am 
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Ed Engelken wrote:
It looks like the B+ is low. Perhaps the selenium rectifier (CR-1) is weak. Replace it with a 1N4007 and see if the voltages come up to the correct values.

Ed, I checked the voltage at the SR + terminal and it's 138.2 volts, which is about what I should have at pin 6 of the 6CM8. I checked resistance of the primary of the AF transformer and it measured 480 ohms. Could the AF transformer be the problem? Audio sounds good on BC band...?

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 Post subject: Re: No sensitivity on SW on Hallicrafters S-119
PostPosted: Jan Fri 27, 2012 4:08 am 
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The output transformer resistance of 480 ohms is reasonable. But, your voltage measurements are not. If you measure 82 volts on pin 6 of the 6CM8 and 138 volts at the rectifier output, then you have over 100mA going through the output transformer . . . I doubt that is happening! All your plate and screen voltages are low. Re-check your voltage measurements and look for bad connections or miss-wiring. You are losing the screen and plate voltage somewhere.

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 Post subject: Re: No sensitivity on SW on Hallicrafters S-119
PostPosted: Jan Fri 27, 2012 7:27 pm 
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You really need to replace all the paper capacitors. C11 for example is probably part of the problem. Use a 1000 volt here. Check values of all the resistors in the voltage divider chain and elsewhere, they sometimes drift way up in value. Don't play set until this has been done.


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 Post subject: Re: No sensitivity on SW on Hallicrafters S-119
PostPosted: Jan Sat 28, 2012 1:00 am 
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codefox wrote:
You really need to replace all the paper capacitors. C11 for example is probably part of the problem. Use a 1000 volt here. Check values of all the resistors in the voltage divider chain and elsewhere, they sometimes drift way up in value. Don't play set until this has been done.


All the remaining caps are disc caps, so I didn't replace them, although I wondered if I should. It wouldn't take long to change them out, but I though these were more reliable than the paper caps.

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 Post subject: Re: No sensitivity on SW on Hallicrafters S-119
PostPosted: Jan Sat 28, 2012 4:41 pm 
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Ed Morris wrote:
All the remaining caps are disc caps, so I didn't replace them, although I wondered if I should. It wouldn't take long to change them out, but I though these were more reliable than the paper caps.

There should be no need to replace disc capacitors. They fail only in very rare circumstances.

There are things in your voltage readings that just don't seem to add up. If you are really getting 138 volts at the output of the selenium rectifier then then R11 (1 W) would likely be seriously hot to only have about 65 volts at the plates of the first 2 tubes.

Dropping about 60 volts across R11 (looks like 1.8K but blurry) comes out as about 2 Watts.

As Ed pointed out the voltage reading also means 100 mA to the plate of the output tube, but the cathode voltage says the output tube is only pulling about 5 mA.

This all seems to circle back to the output of the selenium rectifier. It appears that it can't be the voltage being reported unless there is something else in the circuit or ground isn't ground.

Make real sure the ground for the transformer is really the same ground as the bottom of the power supply filter capacitors.

Curtis Eickerman

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 Post subject: Re: No sensitivity on SW on Hallicrafters S-119
PostPosted: Jan Sat 28, 2012 5:00 pm 
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check plate and screen voltages with tubes pulled out one at a time :shock:


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 Post subject: Re: No sensitivity on SW on Hallicrafters S-119
PostPosted: Jan Sat 28, 2012 7:15 pm 
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Given that the S-119 was available in both kit form and factory built, I would check the wiring carefully. A wiring error could explain the goofy voltage measurement results. First thing to do is to check to see if the red wire from the output transformer really goes to the rectifier cathode.

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 Post subject: Re: No sensitivity on SW on Hallicrafters S-119
PostPosted: Jan Sun 29, 2012 5:46 pm 
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Problem solved! :D Quite by accident. I went out this morning to begin troubleshooting the radio, but first decided to remove and repair the fiberboard back which was broken and wobbly. I found one of the antenna leads from the ferrite rod to the selector switch terminal was broken at the antenna terminal just making contact by proximity.

After gluing a refinforcing strip of masonite to the base, I connected the antenna with gator clips and now it is working properly on shortwave.


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 Post subject: Re: No sensitivity on SW on Hallicrafters S-119 -- FIXED!
PostPosted: Jan Sun 29, 2012 7:16 pm 
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so the low voltage readings is because... ?


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 Post subject: Re: No sensitivity on SW on Hallicrafters S-119 -- FIXED!
PostPosted: Jan Sun 29, 2012 8:51 pm 
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Well, I'm back to where I started. :( When I reinstalled the back after the glue dried, and soldered new leads, I am back to the same problem as before. Very good reception on BC, poor on SW. Touching the loop stick antenna improves the strength of the signal on short wave. While I was waiting for the glue to dry, I cleaned the contacts on the band selector and tightened up the contacts, and I checked all other connections for broken wires or bad connections, and checked that pins were making good contact in the sockets. I've also cleaned all the tube pins. I've also swapped out the 6BE6 and 6BA6 with no improvement. I'm thinking there's something very simple I'm missing.

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 Post subject: Re: No sensitivity on SW on Hallicrafters S-119 -- NOT FIXED
PostPosted: Jan Sun 29, 2012 9:07 pm 
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Ed, I think you need an external antenna for shortwave. That might explain why it worked better when the BCB loopstick was connected with clip leads.
I too am wondering about the voltage discrepancies

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 Post subject: Re: No sensitivity on SW on Hallicrafters S-119 -- NOT FIXED
PostPosted: Jan Sun 29, 2012 10:06 pm 
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cant see the entire print. BAND 2 & 3 PRIMARY on the selector switch may have something to do with the SW antenna connection and where the long wire should be connected :shock:


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 Post subject: Re: No sensitivity on SW on Hallicrafters S-119 -- NOT FIXED
PostPosted: Jan Sun 29, 2012 10:38 pm 
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tubeAMP wrote:
cant see the entire print. BAND 2 & 3 PRIMARY on the selector switch may have something to do with the SW antenna connection and where the long wire should be connected :shock:

Yeah, I think the upper end of L2 goes across (off the top of the scanned schematic) to that terminal conection on the left that is probably labelled something like "Ext. Ant." (also not showing on the scanned schematic).

If he hooks at least 15 to 30 feet of wire to that point and strings it around the room he will have at least some antenna. Without it the radio won't do very much on SW. Of course the more wire the better (at least up to a point).

None of this explains the weird voltage readings, but at least it might work and will definitely be better than no antenna on SW.

Curtis Eickerman

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 Post subject: Re: No sensitivity on SW on Hallicrafters S-119 -- NOT FIXED
PostPosted: Jan Sun 29, 2012 10:59 pm 
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Eickerman wrote:
tubeAMP wrote:
cant see the entire print. BAND 2 & 3 PRIMARY on the selector switch may have something to do with the SW antenna connection and where the long wire should be connected :shock:

Yeah, I think the upper end of L2 goes across (off the top of the scanned schematic) to that terminal conection on the left that is probably labelled something like "Ext. Ant." (also not showing on the scanned schematic).

If he hooks at least 15 to 30 feet of wire to that point and strings it around the room he will have at least some antenna. Without it the radio won't do very much on SW. Of course the more wire the better (at least up to a point).

None of this explains the weird voltage readings, but at least it might work and will definitely be better than no antenna on SW.

Curtis Eickerman


Curtis, Sorry about the chopped off schematic. Didn't realize I did that. I have the radio connected to a 70' long wire antenna. I've just replaced the selenium rectifier and have the correct voltage at pin 6 of the 6CM8 now, but it didn't improve reception. I'm getting ready to do another set of voltage readings. Touching the ferrite rod BC antenna still makes a big difference in reception on SW. When I had the ferrite rod hooked up with gator clips as in the photo above, SW was working great. I have a feeling I've got some issue around the band selector switch or in the RF section somewhere.

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 Post subject: Re: No sensitivity on SW on Hallicrafters S-119 -- NOT FIXED
PostPosted: Jan Sun 29, 2012 11:24 pm 
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Agree, check the path between the external antenna terminal and the bandswitch. The "juice" from the antenna is not making it through.


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 Post subject: Re: No sensitivity on SW on Hallicrafters S-119 -- NOT FIXED
PostPosted: Jan Sun 29, 2012 11:57 pm 
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I connected the external long wire antenna directly to L2, with no change. But out of curiosity, I connected it to B1 on the band selector switch, the same point the loop stick connects, and I get pretty good SW reception on bands 2 and 3. Still haven't done new voltage checks yet. I'm relaxing with an adult beverage, so I may wait until tomorrow. :lol:

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 Post subject: Re: No sensitivity on SW on Hallicrafters S-119 -- NOT FIXED
PostPosted: Jan Mon 30, 2012 12:19 am 
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I'm picking up Havana Spanish language broadcast loud clear with the external antenna connected directly to the B1 terminal of the band selector.
Correction: my external antenna is still connected to the terminal on the back of the radio. I ran a jumper from there to B1. Connecting the external antenna directly to B1 terminal (and bypassing L2) just produces static. Sorry for the confusion. Too much adult beverage? :D

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 Post subject: Re: No sensitivity on SW on Hallicrafters S-119 -- NOT FIXED
PostPosted: Jan Mon 30, 2012 12:53 am 
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Ed Morris wrote:
I'm picking up Havana Spanish language broadcast loud clear with the external antenna connected directly to the B1 terminal of the band selector.
Correction: my external antenna is still connected to the terminal on the back of the radio. I ran a jumper from there to B1. Connecting the external antenna directly to B1 terminal (and bypassing L2) just produces static. Sorry for the confusion. Too much adult beverage? :D

OK, from the earlier post it looks like the voltage problem has been solved by replacing the selenium rectifier. Now for your antenna connection.

As you switch from Broadcast to SW1 and SW2 the bandswitch is (or should be) moving from B1 to B2 and then to B3. You see inductors connected to B2 and B2 which are actually two different secondary windings on inductor L2 which is your antenna connection from the external wire.

An ohmmeter check from the external antenna connector to ground should show some kind of continuity. I'm guessing less than 100 ohms. If it reads infinity then L2 primary is open and L2 needs to be examined more closely. Likewise you should see continuity from B2 to ground and from B3 to ground or again look at L2 very carefully for a broken or unconnected ground wire.

Basically L2 is really a matching transformer to help make your short antenna work properly on the two shortwave bands. There probably is an adjustment procedure for setting L2 properly to work on the two bands, but first you need to make sure you don't have a broken or missing wire. For what it's worth the schematic is drawn wrong and should have shown L2 as T2 (or T something) and shown that it is coupled to the other two inductors that are not labelled, but that's the way it goes.

Curtis Eickerman

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