I had fun this morning. I started up my 1952 Hallicrafters S-40B receiver today, very carefully. I first cleaned the controls, then plugged in the receiver with my Variac and Dim-Bulb-Tester in line. Slowly brought the voltage up listening for hum, watching for smoke. There was a very slight 60 Hz hum at the beginning but that went away.

It's working on 80 volts right now. I thought it best not to bring it up to 110 VAC, the standard household voltage that was common in the 1950s. Here at the house I have 122 VAC. I left it running for over an hour, nothing bad happened.

So given that, I'll go ahead and replace all the capacitors (ordered Harbach) check for out of tolerance resistors, etc. Clean it up. It's really dirty, which is actually a good thing, tells you no one was inside messing around. It looks to all original.

I'll bet this is the first time it has run in decades. Just goes to show you they built (made in the USA) really good stuff back then, built for the long haul, repairable, to last many generations.

73, Richard AG5M

Don,

The original is completely absent.? All I have are some pictures that I found online and one from a guy at ARF.?

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I did verify that the meter drive circuit works by wiring up the meter from a Johnson Matchbox.? I adjusted no signal = full scale and as I tune a strong signal, the needle moves to the left...

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I'm also chasing down a distortion issue with (I think) the 6SQ7 detector circuit, so the radio is open and on its side again :)

Thanks, guys.? Anyone know where to find one of these backward meters?? I've seen some posts around where people claim you can adjust a regular "left zero" meter to become a "right zero" using the internal or backside adjust.? Maybe better to start with a "center-zero" meter since it's only half the distance to the goal.

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I thought about the upside-down method, and it may work.? The angle of the needle will be wrong though.

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You know, sometimes a fellow needs?to follow his own advice.?

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I have been working on an SR-160. As of this morning I had put 12 hours into it. I was getting nowhere. I spent considerable time ensuring that all alignment was perfect. Every time I turned it on it acted differently. I don't know why, but?I started wiggling tubes. Almost every tube brought forth loud crashes from the speaker. I said to myself "Well dummy clean the tube sockets and pins".?

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Guess what, I now have the sweetest running SR-160. The receiver is running 22 to 26 db s+n:n. The transmitter runs 120 to 135 watts across all three bands.

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Well, that was my last rig on the shelf. So now I am looking for another project. I have not had a HT-40 on my bench for 15 or 20?years. So, I am looking for a complete unit. It doesn't need to function as long as it has not been butchered inside and has a readable front panel. So anyone with one that has been on the back shelf for years and is willing to part with it contact me off forum.

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?73

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Don,

Australia runs 230VAC 50 Hz but typically measures around 240VAC. The arrangement you described sounds like our wiring. The system we use is called MEN or Multiple Earth Neutral system in that the cold (or neutral) line is grounded at the point of entry to the house (at the fuse/meter box) via a copper stake into the ground. The hot, neutral and ground wires are extended to all outlets. I believe the multiple earth neutral terminology comes from the fact that there are lots of points along the distribution route where the the neutral is grounded, not just at the source.

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I intend to use a three prong plug and ground the chassis. As far as the ON/OFF goes I will probably rewire it so that it is in the primary of the transformer if I install it in the cabinet.

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As an aside, so far, every resistor? I measured (except R20) has been way out of tolerance (high) to the point that I double checked my meter against some known values. Also, R20, the 1000 ohm 1/2W resistor in the B+ line has been replaced at some stage with a 1 Watt resistor and it is showing severe signs of burning, but still measures 1000 ohms.

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Cheers