First Boatanchor semi restoration

[KC4KFC]

Just would like to relay my beginners experience.

I found a TransOceanic 8G005y with the octal tubes and the push pull audio in an antique store in Maine this summer. Maybe I paid too much according to prices on EBay but......

I resisted the temptation to plug it in until I put new electrolytics in the power supply but once I did I aligned it and I must say, it is a remarkable radio. BC band receives stations across the entire band. I have been regularly listening to Reds baseball as well as the evacuation from New Orleans during Gustav. Cleveland, Louisville, Pittsburg, Lansing, Atlanta, Chicago, St. Louis, etc. booming into Nashville. This is a fun radio! Shortwave works well I think but I am surprised at the poor propagation. I used to get Radio Australia in the morning no problem on other receivers years ago but now only CRI on the 49 meter band and I think they are relayed. Anyway, I am very impressed with this 1947 era receiver.

So I got to thinking, I have had an SX-101 in the attic that I got at a flea market for $10 maybe ten years ago. I hefted it to my workbench and it looked really hopeless. Lots of rust and corrosion on the chassis, chipped tuning knob, power cord falling apart...... but the glass is good and the radio is complete except for the needle alignment knob. Warning signs were broken dial string and a 20 amp fuse in the fuse holder. It should be two amp. I went to work on the gears with solvent and lubricant and cuetips etc. The paint behind the plastic light diffusers was all flaking off even getting into the meter. I vacuumed and scrapped it away and put some bright white paper as a reflector there.

Wire brushed the rust off the chassis, cleaned as best I could the tube shields, etc. Replaced the fuse and power chord. Painted the body with a close matching silver and gloss black. Cleaned the front panel nicotine and dirt. Still some deep scratches but what the heck. This is not a complete restoration.

So I put a meter on the electrolytics and they seemed to charge so I couldn't resist it. I plugged into my variac and brought it up to 50v for a while. The band light bulbs barely came on which was good because I had taken them out and didn't know where they went. More voltage slowly. I tried to get the needle back in the same place by measuring the old dial cord and putting the needle back as the old one.

Plugged in headphones and heard some hum. Not huge but noticeable. Slowly bringing the variac up to 90v ... no smoke...no smells. Now I heard some audio amp sounds when bringing the volume up. More voltage to 110v.

Moved the dial across 80 meters nothing. Oh, the RF sensitivity on 0.... Opened up the sensitivity to about 7 and SURPRISE! I heard ssb. I can't tell you how exciting it was to hear this thing begin to work.

Voltage now to 115v and I stuck a wire into the antenna. Played with the knobs and then I hear the South East AM net on 3886. And the dial was dead on frequency. Played with AVC and all the bandwidth choices. Everything worked except the notch filter and I haven't read the manual as to how it works.

Lots of signals on the AM net. Meter was dead until I swapped the leads. Now it moves great from S0 to 80 db over. I think it amazing that this thing played after sitting in my attic for over 5 years and so rusty and corrode it obviously sat in awful conditions for years.

And the first thing I tune into and listen to is the AM net along with boatanchors across the southeast!

There is still the hum so I won't play it again until I replace the electrolytics.

Sorry to be so verbose, but I wanted to share my thrill with bringing back this cool radio. I have only aligned a few radios before. I have never really restored anything. I have worked a little on guitar amps but thats all. But I think I am hooked on this. Even thinking I need to find something like a SX-62 or something general coverage. with push pull audio?


de KC4KFC

Mark

[Todd, KA1KAQ]

Congrats, Mark - nothing wrong with sharing the excitement, oftentimes it prompts others to undertake postponed projects or to find new challenges.

The early T.O.s are really sweet boxes, incredible sound and performance for such a simple, straightforward radio. I have a nice H-500 that gets used from time to time, it always amazes me how quiet the thing is, how well it receives, and the overall tone and quality of the audio. Paid a whopping $10 years ago when someone brought it into my shop to see if I'd buy it. You betcha! Those 1v tubes last a looooong time, I've yet to change one.

Your SX-101 sounds like the perfect candidate to bring up just as you described. If you're not sure or just want to experiment, a beat up old 'dawg' that many wouldn't pay the time of day to seems like a great way to gain knowledge. Nothing rare or scarce that you'll have regrets over if something smokes. Once you get it working you can decide what to do cosmetically.

We don't hear a lot of 4-Land AM activity up this way, so it's nice to read your report. Activity begets activity, and 'radio season' is almost upon us.

[WQ9E]

Mark,

Congratulations on your dive into boat anchor land.  You have started with a couple of nice models.  I picked up my first Transoceanic several years ago (in an antique store in Maine while on my honeymoon proving I have a really great and understanding wife!).  I always think of the Bogart movie, "Key Largo" when I have one of my Transoceanics playing out on the gazebo.  A great tech resource for these radios is Padgett's web page:  http://bellsouthpwp.net/p/a/padgett46/index__1.htm  and his tech tips are advised reading.

My main novice receiver was an SX-101 (the early version covering 160) although I used an SX-62 for the first week or so.  I still have several SX-62 receivers and they look neat and sound great.  Restoration is a little more difficult with the key problem being the hard to reach caps in the front end.  But you can replace them without taking the receiver apart and the access panel on the side really helps.  I have also found that one or more of the mica caps in the FM discriminator was leaky in every SX-42 and 62 I have gone through so count on replacing those but I have only run into one leaky mica in all of the other IF cans so those seem to hold up OK.

Again, congratulations on jumping in with both feet and bringing a receiver in really rough shape back to life.  With its selectable sideband, notch filter, and 50Kc IF bandwidths with good skirt selectivity the SX-101 is one of the best "battle conditions" AM receivers out there.

Rodger WQ9E

[W1UJR]

What, you were in Maine and did not stop by my place?
http://www.atlanticmotorcar.com/findus.htm

All kidding aside, the Route 1 Antique Trail is great for radio finds, I prowl it every weekend.

You didn't happen to pick up the Zenith from the "Great Chicken Barn" in Ellsworth, did you?
Saw one there earlier this summer, almost bought it, but I was on my way to Nova Scotia and did not want to deal with Customs.

Congrats on jumping into restoration, its very addicting!
Any photos of your find, the early T/Os are wonderful rigs.


-Bruce

[w3jn]

The SX-62 is a challenge to re-cap for even the most experienced restorer.

Congrats on bringing another one back to life!  The 101 is a FB receiver indeed.

[KC4KFC]

Thanks all for the encouragement!

Bruce! Yes! It was at the chicken barn! I saw it early August and went back for it a week later hoping it was still there. Maybe overpriced but they had a 20% off sale and the inside is pristine.

We stay in Rockport for vacation every summer. Beautiful, beautiful country up there! I must have driven by your place several times!

I did listen on my IC-706 and 20 meter endfed wire and heard some amazing AM on 3886 thereabouts. I distinctly remember hearing K1KBW with Class E amp pegging my meter 80 db over from Ct. and W2JBL and others. I guess thats the East Coast sound? Wish I had brought better headphones. My antenna was not too far from the water but propagation none too good.

I have ordered some good caps for the SX-101 and can't wait to align it. Maybe I need to find the matching transmitter now.....

Thanks again,
Mark

[w3jn]

We stay in Porkrot for vacation every summer.

Fixed that for ya.

Thanks again,
Mark

Not at all 

[AF9J]

Way to go Mark!  It sure is a good feeling getting a radio running, that was neglected for who knows how long isn't it?  Like others have said, feel free to post away about your restoration triumphs, and your restoration setbacks.  I sure did.  It was a great feeling to get both my Johnson Viking II going (when I got it [for $75 last November], it was a non-runner, that hadn't been used since who knows when [it took me 20 minutes alone just to vacuum the dust out of it), and my Drake R-4A (it looks ratty, but it runs great after doing a little work on it [it was a cheapo eBay find).  You'll find plenty of help here on the AM Forum (I can't thank Rodger, WQ9E enough for all of his expertise and help).

73,
Ellen - AF9J

[WQ9E]

Ellen,

Thanks so very much!  It is a pleasure to help people with vintage gear and it is a lot more fun than my "real" job of marketing professor. 

Now away from the fun and back to writing a book.  I keep telling myself that once I finish chapter 1 the rest is going to be easy.  Maybe if I was writing a book about vintage gear instead of enterprise risk I would enjoy writing a lot more-unfortunately the market size for vintage gear info is a lot smaller.

Rodger WQ9E

[W1UJR]

Thanks all for the encouragement!

Bruce! Yes! It was at the chicken barn! I saw it early August and went back for it a week later hoping it was still there. Maybe overpriced but they had a 20% off sale and the inside is pristine.

Hi Mark,

Yep, it may be that it was the same rig. Was located on the left hand side as you enter the shop, seem to recall it had the power cord cut off and replaced with a black cord? I think also it had a white knob on the front.

If its the same rig, I picked it up, almost bought it, it was in nice shape! But I was defiantly there there the last week in August, August 25 to be exact, so perhaps there were two T/Os there? I had considered going back for a radio rescue, but sounds like you may have gotten the one.

A few year ago I walked out with of the place with about 50 Radio News from the 1930s, they were happy to see them gone, and I was happy to get them. I check when I visit, but most of the ham mags are now 70s vintage.

Email me off line, and I'll tell you about another secret radio place on the coast, closer to Rockland.

[WA5VQM]

Hi Mark!

I feel it necessary to jump in here and express one of the significant dangers of boatanchor restoration: it's addictive!

It's a great feeling to take an old neglected rig that's been dark for who knows how long and bring it back to life. Some take more coaxing than others, but it's a worthwhile thing to do. Anything that keeps them out of the landfills is a good thing. That '101 is a keeper fer sure.

Congratulations, and have fun. Hope to work you on the air!

73, Mark (also)

[KC4KFC]

I'm having fun changing out the paper caps. Changed the electrolytic caps in the filter section but that didn't cure my hum which surprised me because it sounds like power supply hum. The hum starts as soon as I turn the set on before the tubes warm up and start to amplify.  The filter choke reads correct dc resistance. I do have an oscilloscope but am not sure about using it.

The chassis does have some rust especially around some rivets, maybe a ground is bad.

I have been changing the caps using Orange Drop 716p s. I hope these are the appropriate choice. The old caps are red "Tiny Chief"'s.  I do them one at a time and then turn on the set to see if I screwed it up or fixed the hum.  I'm about half way through. I started at the 6F6 audio tube and working back. 

 Bruce, that was the same TransOceanic. Funny, 1200 miles away from each other and we looked at the same radio! It really plays nice and I actually heard a station (Radio Australia) in the 16 meter band about 17.8 Megacycles!

Mark
KC4KFC

[WQ9E]

Mark,

Is your hum coming from vibrating transformer laminations (or maybe the choke) instead of the speaker itself?  Pull your output tube and see if the hum continues.  By the way, shouldn't that be a 6K6 instead of a 6F6 in the output stage?  I have an SX-101 Mk2 and an SX-101A which both use the 6K6 and I thought the whole line did since the 6F6 is a very "vintage" output tube.

You may need to lubricate the bearings in the tuning cap if the tuning is stiff.  It should be very smooth on these receivers and I have had to do this on a couple of them.

Rodger WQ9E

[KC4KFC]

Roger,

You are correct, I was mistaken, the audio tube is an 6K6 and glows lovely blue. Also, funny thing, the Hallicrafters pressed cover for the power transformer was vibrating but the hum was in my headphones pretty loud.

I did some searching on this forum and thought maybe its the headphones which are quite bass heavy. I don't have a 3.2 ohm speaker but I do have the Signal Corps speaker for my BC-312 which is higher impedance. I measure DC resistance at 392 ohms so maybe this is a close match to the 500 ohm connection on the back of the SX-101. It sounds good and the hum is hardly present. Wonder if I should just leave it alone or get headphones with rolled off bass.

So I have probably listened to this receiver 3 or 4 hours so far and it is doing good. Caps made the audio clearer and the set seems stable. There are still a few of the black tubular caps (Black Beauties?) but I am not sure if the color band code is the same as resistors.  I left the caps on the selectivity switch as they look extremely difficult to change and the selectivity seems to work very well.

I haven't aligned it yet. 20 and higher seems less sensitive. 40, 80, and 160 have gain to burn and I keep cutting back the RF gain (Sensitivity). Audio is nice with an amazing fullness in the bass. I'm very pleased with my $10 Hallicrafters. (I paid more for the caps!)

I have cleaned the tuning cap brushes with wire brush and also lubed the gears etc. It doesn't spin from end to end but it does flywheel a little.

I assume I should have it in the case for alignment.

Changing out the caps was not as hard as I thought. I might not have the steadiest hand but a couple of evenings and done.  I will get out the camera and post some shots.

Thanks for the encouraging words everyone; would be great to see yall on the air!

Mark

[WQ9E]

Mark,

Hmmm, how much blue glow?  You might be needing a new output tube shortly since yours may be gassy!  Also, I assume you already replaced C-97 but if not that is a critical one since DC leakage here will reduce the negative bias on the output tube leading to collateral damage (output tube, transformer, potentially even the power transformer).

If your headphones are of the modern low impedance variety you will hear significant hum on most of the older tube type receivers.  As I recall you stated you have hum before the tubes warm up so the hum in your sensitive headphones may be due to coupling from the power transformer to the audio transformer; this happens in a number of receivers but it is generally not noticeable with "communications quality" headsets.

Before you do a lot of alignment work, check the oscillator frequency of the two crystals in the 2'nd converter (one is at 1600 and the other is at 1700 khz.).  If one or both of these have drifted off a bit you can compensate by slightly changing the alignment frequency for the final IF.  You can check these by listening to them in an external receiver (with an accurate digital readout) and tuning for zero beat.  If yours are very far off let me know and I will give you a quick synopsis on calibration of the final IF.  There isn't much on 20 and up these days so sensitivity may be OK; the old quick check if you don't have a calibrated signal generator is to connect the receiver to your antenna and run the audio gain up a ways.  Then adjust the antenna trimmer and if you can hear a noise peak you pretty much have all of the sensitivity you can use although it still wouldn't hurt to go through the alignment procedure.

Enjoy the SX-101, it is one of my favorites!

73, Rodger WQ9E

[KC4KFC]

Thanks Roger,

I think the audio tube's blue glow is not too excessive. I am not sure but seems to look like some 6L6's I have seen.

I am impressed with the sensitivity on the lower bands but will check the converter crystals as you suggest. If C-97 is the electrolytic for the cathode bias, yes I did change it.

I did hear some Short Wave broadcasters on 20 last night. I think it was Radio South Korea on 14.175 or thereabouts. Also several other AM broadcasters in Spanish. I don't know that I have ever heard commercial stations on 20 before and thought maybe I was getting a harmonic or something but not sure. But I get cw where it should be and SSB where it should be.

Thanks for the voice of experience. I have only aligned my Trans Oceanic and some other AM sets. I do have a Heat Signal generator I zero beat with my Icom 706 and I have the manual which looks quite complete for alignment procedures. All help is very much appreciated.

I will be too busy to get to it this week but I will post my progress or lack of progress by next week. I did change the 12by7 for one I had in my stash. Original tested weak. I won't leave this set plugged in all the time because of it and the heater gizmo. Wonder if I should just snip it and cap it off?

I wonder which model transmitter matches the SX-101. HT-30 maybe?

Thanks,

Mark
KC4KFC

[w3jn]

HT-32.  The HT-30 matches the SX-100 and the SX-96.

Sounds like you're getting images, which indicates the front end is out of alignment.  Be careful as those slugs in the front end are sealed with wax and/or varnish - don't force 'em or they'll break.  Remember to use as little signal from the sig gen as you can to get a deflection on the meter.

The 12BY7 is *always* bad in SX-101s.  Dunno why.  The sockets are also often charred.

For better AM fidelity (less distortion) at the expense of the noise limiter, cut one end of the .1 uF capacitor associated with the noise limiter.  This decreases the capacitive loading on the detector, allowing less distortion on heavy modulation peaks.

[KC4KFC]

Thanks John.  BTW Porkrot cracked me up. And also I have read your article on receivers many times -- great info.

I am all for less distortion so I will try the limiter cap trick.

The 12BY7's filament runs any time the set is plugged in regardless of whether its on or not which I am sure you knew. I downloaded the schematic for the SX-101 MKI which actually shows a 12AU7 instead of a 12BY7 . I wonder if they are interchangeable.

What was weird with the image was it sounded great. Not too strong but full clear AM.

Thanks!

Mark

[KC4KFC]

So the SX-101 has some issues. Two slugs are missing from the antenna inductors for 40 and 20. Weird. They are just gone. No trace of the wax or whatever they pot them with.  Peaked up the other bands though and the oscillators. They were surprisingly close. One of the oscillator trimmer caps for the 20 meter band is broken but I think I got it to stay where it should. I don't know for how long.

160 and 80 perform well so far. Its still on the bench......

[WQ9E]

Mark,

The 12BY7 and 12AU7 are not interchangeable but the 12BY7 is probably cheaper than the AU7 now since there isn't an audiophile demand for them.  The idea behind the constant on filament was to reduce warm-up drift.  You probably also have a resistor wired across the line to keep the chassis warmer.  My SX-101A uses the 12BY7 and has the warming resistor along with an errata sheet since Hallicrafters originally called it a Dampp Chaser and that name is trademarked by the company who made them and since they didn't purchase that particular resistor they had to remove the name from the manual.

In general I don't think it is a good idea to leave vintage equipment plugged in when you are not around.  Switches fail, line bypasses leak/short, and other bad things that can result in fire might happen.  In my ground floor radio room (formerly the parlor), I have the 120 volt gear plugged into 3 power strips and I kill the power to these when the gear is not in use.  The Johnson Desk, Drake L-7, and Collins 30L-1 all run off 240 volts and I have a separate kill switch for the 240 volt line to this room.  The main basement shack (what my wife refers to as the museum) is wired with a shutoff switch leading to a separate breaker panel which powers all of the tables and shelves in there.  The only things live all of the time are the main lighting switch and one set of outlets used for things other than radio gear.  Disclaimer:  I have spent the last several years working in the area of enterprise risk management so I am probably overly cautious-it comes with the territory.

Rodger WQ9E

[KC4KFC]

So I made a mistake. The missing slugs were that way from the factory I think. I took the slugs from one of the 10 meter inductors and put them in the missing places and each one was better without one.

Everything seems to be aligned well now. Each band improved sensitivity.

My Heath signal generator was very weak at 28mhz so I used the harmonic of 14mhz on the 10 meter band. Got the broken osc cap repaired with a touch of glue. Probably not the best fix but it is working so far.

Rodger, yes mine has the Dampp Chaser (two P's). The schematic for the SX-101 MKI is same for this radio but there is a mistaken OSC coil number. Took me a little while to figure that one out.

Its back in the case, screws in place and looks and plays pretty good!
Thanks all for the help.

Mark

[Steve - WB3HUZ]

http://www.hfunderground.com/wiki/Porkrot

Although they have the state incorrect.

Thanks John.  BTW Porkrot cracked me up. And also I have read your article on receivers many times -- great info.

I am all for less distortion so I will try the limiter cap trick.

The 12BY7's filament runs any time the set is plugged in regardless of whether its on or not which I am sure you knew. I downloaded the schematic for the SX-101 MKI which actually shows a 12AU7 instead of a 12BY7 . I wonder if they are interchangeable.

What was weird with the image was it sounded great. Not too strong but full clear AM.

Thanks!

Mark