Indulge an old man for a minute – and learn a new skill in the process!
You see, my pal of 71-years (The Major) is in recovery from a knee replacement this week. So, I thought a return to those “thrilling days of yesteryear” might have some curative effects.
The scene-setter, therefore is the old Owens Pharmacy at the intersection of 15th Ave. South and Beacon Ave. South in Seattle circa 1963. Because they had two things of keen interest to young ham radio sorts as we were at age 13 or 14.
In addition to a totally smoking hot pharmacist (long brunette hair, yoga practitioner, too) they also had a tube checker. Sadly, we spent most of our time there with the tube checker.
Back in this era of electronics there were no chips, only a few solid-state diodes, and even most of these were still selenium stacks. But when a radio stopped working, it was – often as not – merely a vacuum tube gone awry. Easily tested…and a useful skill if you want to restore old TVs or Fender amps, for example.
First You Need a Tube Checker
The one at Owens was a counter-height base where a bevy of tubes was kept under lock and key. Those were the store’s inventory. The top was where the testing took place.
Never to be caught short, I somehow still have three tube checkers, since I’m an old school radio and high-speed Morse code kind of guy. Your “checkout” will be on this one: A B&K Precision DynaJet tester:
The high-level view of the process goes like this:
- Once you have a tube checker, select the suspect tube you want to check.
- Look at the tube number.
- Find the checker/tester settings in the manual.
- Put the tube in the right test socket.
- Read meter and determine if you need to buy a new tube.
It ain’t rocket science, or neither The Major nor I would have been able to figure it out.
Real Life Application
Step into the Radio Detective’s workspace. Here we see that Drake 2B receiver that was resurrected this week. The radio had almost no audio coming out of it. Which didn’t seem to be caused by my defrocking the case from it or running it upside down on the workbench…
Later, it would be found that the previous owner – a member of the Royal Soldering Society, had attempted to replace the specified tube (an 8BN8, which wasn’t terribly common) with something else. In the process, the wiring turned to spaghetti, but a lot of radios coming across my bench seem to be plagued with either soldering idiot or Golden Screwdriver recipients lately – but that’s another column.
Point is, after the 8BN8 tube, the next stop on the way to the speaker is a tube numbered 6AQ5. Real common, generally reliable tube. But you can’t take chances. We measure and test. Like stock trading, measure and look for results, right?
Here’s your first hint at becoming a tube testing expert. When you have a tube where the lettering is not clear, like our 6AQ5 friend here:
You can gently rub the tube on the short hair of your neck and the numbers will become more legible. This seems to work on all the glass tubes I’ve tried it on; it doesn’t work on metal or ceramic tubes, though.
Since the tube was in the 6AQ5 socket in the radio, and it read 6AQ5, the next step was to look it up in the “secret decoder book” for the B&K tester.
Starting with the black arrow, we ignore the previous tech’s note and notice the “Heater voltage” for this baby is 6.3 volts. The “A” knob (*follow the red arrow down) is set to “35” then the “B” set to “1” and “C” to “7” as the knob settings are completed.
Last column (green circle) is the tester socket to plug the tube into.
A double check of everything, then we put it into the tester and wait 12-seconds. Because, say the books, typical warm-up times on this kind of tube run 11-seconds. (The Major would stare at the meter at the drug store tester. I was trying to catch an eyeful of hot brunette…) Eventually the answer was at hand:
If this was going in a balls-to-the-wall small tube amp – where a pair of 6AQ5’s might pretend to do 20-watts between a pair of them – it would have been too weak. Pushing out CW tones for an old man? It was fine. Back into the radio and resume rewiring the 8BN8 into working again. Which happened 45-minutes later.
Radio Detective Story #2
Hallicrafters HT-40 transmitter repair. And another example of when you buy used ham gear on eBay, often as not it won’t work because if it is working, they’d tout that and get more money for it.
You will remember from our gentle introduction to electronics troubleshooting that capacitors usually go first? That’s why these new caps now live in the HT-40.
The old ones which weren’t replaced yet, had failed to ground and taken out two diodes and one power resistor in the (cheaply designed) radio.
As luck would have it, yes, I do have a deep store of radio parts, so I was able to walk over to the 10-watt power resistor department and find the ideal replacement. While down in the solid-state devices department, there were some high-speed power diodes, too.
By the way, a second ago I referred to the HT-40 as a cheaply made radio – the kind of thing Hallicrafters didn’t do much of. But I’m not the only one with that opinion. See for additional depth the article HALLICRAFTERS HT-40 (wireless-girl.com), She totally rocks old radio gear and her take on the Johnson Pacemaker, which is also in pre-op here, is very close to my own.
Been a busy week in the radio department. Too damn hot to do much outside, and next weekend will be devoted to setting up the more formal-looking ham radio bench. The tentative layout will be four layers of equipment. Low power (QRP) and up to 50-watts on the desk level and then three layers of acacia wood butcherblock style (60-inches long) above.
These were finished out in the shop with 3-4 coats of sanding sealer and then a couple of layers of triple-thick varathane. Elaine popped her head in this week, long enough to say, “You’re not really going to cover that beautiful wood with RADIO gear, are you????”
“Well, um, yeah honey…”
Second layer up will consist of the solid-state gear. One or both of the Icom 761’s, the TS-590, and the TenTec Jupiter plus an MFJ roller inductor tuner for the open-wire antennas.
The third layer will include the Hallicrafters version of the Collins S-Line. An SX-117, the HT-44 and matching power supply, plus the Loudenboomer (HT-45) amplifier. T.O. Keyer. The top row is still undergoing feverish debate. Another Hallicrafters radio? SR-150 is ready. An Icom marine M710 for channelized ops, digital modes, and ALE?
A lot of the time, so far, has been in working out details of the build of the dream radio setup. Like so many things in life, the fixing-to-get-ready takes more time than the actual build itself should. But we shall see. Might get started on it over Labor Day weekend.
Write when you get rich,
George@Ure.net
So, speaking of tubes, how should we interpret ZZ Tops…
“Tube Snake Boogie”?
I got a girl, she lives on the hill
She won’t do it but her sister will when she boogie
She do the tube snake boogie
Well now, boogie, little baby
Boogie-woogie all night long
Blow your top, blow your top, blow your top!
Tube testing was done by the public back then, mildly complex. i don’t think we expect such high cognitive behavior today.
Did you offer to check the Pharmacist’s tubes?
Yo G
timely conversation this AM regards Tubes and the warm glow they seem to emit when powered up. Tubular dude!
Unscheduled tube test this AM in BCN house, woke up to a tube on full power?
I mean the badboy was glowing..throbbing almost. Whats a dutiful Man to do ? https://youtu.be/U9DZkj8Rq6g?si=xTDDDWiMG98q_EzX
Thankfully, Mrs BCN was the cutie on dutie – and took care of monitoring the powering up cycle to max output, for me !
yes – I must agree wit you – there is NOTHING like the warm glow of a “tube” in the morning, or any other time for that matter.
Hi, George,
I would imagine that the Major already knows this, but it is important enough to please remind him. After knee replacement surgery, it is imperative that he gets up and walks around the house and walks around the streets near his home. He absolutely must do his physical therapy, and he needs to take the pain meds offered so he can stay ahead of the pain while exercising. I have had both my knees replaced, and it is a wonderful thing to be able to walk and hike again. I hope he does just fine.
Yes mam!
But he doesn’t need me to remind on that one. Although his wife was in as an O3 (Captain) the way things work is the Major (O4) salutes her. And since she’s a PhD now…he, um, snaps to and salutes even at the mention of a “direct order” from HQ, lol.
I’ll pass it along, though…
BTW their genius level son, doing his PhD is about to make O5…A very orderly outfit, indeed!
There is no sound better for a guitar then a tube Fender amp.
Except when it’s me picking at it, lol!
Lol lol
I get paid whenever I sing………
yup they pay me to stop lol lol
Guitar amp tubes are an unexpected victim of Russia’s invasion on Ukraine…
The other day, Electro Harmonix owner Mike Matthews — the guy who invented the notorious Big Muff — sent out this letter to clients:
Yesterday, Russia imposed a ban on the export of some 200 goods in response to the sanctions imposed on it over the current conflict in Ukraine. We have confirmed that the ban applies to our seven brands of Russian tubes.
Matthews had previously warned of a coming global shortage in vacuum tubes, since they were only being manufactured in Russia, China, and Slovakia. (There is one US company that does boutique tubes for audio equipment other than guitar amps, but uhh, they’re not cheap.) Unfortunately, these tubes are typically handmade, which means high labor costs.
Meanwhile, an estimated 50% of the neon gas required to manufacture the semiconductor chips used in most modern synthesizers come from Ukrainian factories.
https://boingboing.net/2022/03/14/guitar-amp-tubes-are-an-unexpected-victim-of-russias-invasion-on-ukraine.html
George,
What cleaner would U use for mold prevention.
Our basement got some water, close around an inch due to power outage and battery backup sump failed to perform well enough. Others had worse flood, some reason the water utility cut back pressure at same time and those I know with water pressure backup sump pumps lost furnaces and etc.
It was a wicked storm, sounded like a himicane winds wow.
J McCanney used the term himmicane for land wind storms of hurricane strength,
thanks for your always enjoyable discussions on Sundays.
I happen to have that problem that sprung up with super cold ac and the guest bathroom ceiling in the big house.
The first step is to dry the hell out of everying. Install a dehumidifier, too, but that around here means emptying it daily.
The wash it down with a mold killer (wearing nitryl gloves and N100 or better mask). I will be using RMR-86 Instant Mold Stain and Mildew Stain Remover Spray – Scrub Free Formula Amazon link is https://amzn.to/45Mgl0E
For the wipe up, I got a back of cotton shop cloths… Simpli-Magic 78966-100PK Shop Towels 14”x12”, Red, 100 Pack Azmn link https://amzn.to/3sCnXUU Shop towels are like whiskey and vodka – you can never have too much on hand.
Allow to dry well and then, tape off any sketchy areas and hit it with spray cans of Zinsser 287512 Molding Blocking Spray Primer, 13 oz, White Amazon source https://amzn.to/483dCC3
Seems like I tipped my hand on another upcoming STS column, lol
Ozone the he’ll out of it.. then before it dries out…
wear a mask, goggles gloves etc. and take a spray bottle of food grade hydrogen peroxide..and mist it.. the food grade hydrogen peroxide will kill the mold spores.. you can also use a paint roller to spread the hydrogen peroxide out.. deep penetration..great stuff..
Pour food grade hydrogen peroxide into a spray bottle. …
Let it sit for about 10 minutes or until the hydrogen peroxide stops bubbling.
Scrub off the mold with a stiff brush and apply the hydrogen peroxide with a rag or soft brush. …
When finished, wipe the surface dry with a clean cloth or rag.
Repeat if necessary.
let it dry..
ozone the area to kill any spores that are airborne.
I presume you mean the 35% H2O2. Amazon is now selling highly diluted (12% and 8%) H2O2 advertised as “made from 35% H2O2! Big deal. Concentration is everything with oxidizers and a lot of other things. They used to sell the 35% stuff, but for some reason, they are only offering the watered down product. I wonder why?
Is there an easy way to make your own H2O2? There are other places to buy the good stuff, but for how long?
Thanks for the information.
Be careful with red shop towels, wash first, or you could end up with red on your white.
George
I have been doing a lot of research lately to learn the art and science of electronic rotary switch cleaning. My antique Heathkit IO-4550 has developed a switch problem in the Times/CM switch. So I will have to open my wallet to fix it.
First off never never use WD40 to clean a switch or potentiometer!! You will ruin it.
For switch cleaning use a product like DeoxitD5. For the potentiometer use something like Deoxit Fader Lube that will not kill the carbon track in the pot. This is not a paid endorsement of Dexoit, just some info.
For switches that have serious tarnish problems and maybe a mechanical problem with a contact you may be able to disassemble the switch and perform surgery. The switch wafers can be soaked in a solution of white vinegar and salt, (as much salt as will dissolve), to remove the grunge. Kill that reaction using distilled water and baking soda. Contacts not making a connection with the switch rotor can be adjusted to make contact. Just don’t be a gorilla doing it. Treat the switch like it’s a Swiss watch!
For switches that cannot be purchased there is a good possibility of saving them.
The commercial cleaners are expensive but you don’t need a lot to do the job. A little dab will do!
For those who do not know, the IO-4550 is a dual trace dc-10 MHz scope.
The reason I broke down and bought the ;puter-based Owon 25 mhz scope for under $100 is that the old Kenwood and Tektronics both were getting finicky.
There is a really good product for contact cleaning called a chamois stick. The good ones run 50-cents each see https://amzn.to/3KVnaow
Old broadcast engineers (Hank and me) know never to use a Q-tip on a switch because they can leave behind threads that can become an issue.
While chamois sticks are prime choice #1 with DeOxIt 100 on them, the weaker cut of Dox and lesser swabs fall after that. So the second choice is a microfiber swab and foam after that.
The real Craft Fellow in in the radio order will move the wiper to a non contact position between contacts and ever so gentlly press down on the middle of it with a soldering (or dental) pick. This tension is adjusted so that you can just barely see the wiper rise when it touches the contacts.
If you go too far down, the bent up edge of the wiper will have too much friction and that can lead to bending the wiper in which case, good luck finding the switch replacement.
Hope this helps?>
Switches can be finicky to clean… but also video heads. Back in the day of 2″ video tape with the rotating quad heads, the heads needed frequent cleaning to remove clogging tape oxide buildup. RCA and others sold expensive cleaning cloths that, along with alcohol, would remove the grunge without leaving threads behind. Then we discovered something at the local fabric mart, after taking in a sample of our expensive, custom cleaning cloths.
“It’s a twill-weave linen” said the clerk. “How many yards would you like?”
For the next several decades, through a half dozen TV stations, I was the maintenance hero for obtaining cheap fabric cleaning cloths for the video heads. Chopped into 4 inch squares and stacked next to the alcohol squirt bottle for cleaning heads in the video tape room.
I used shotgun patches on ours — soaked in alcohol and followed up with a splicing tape “lint remover.”
I loved those wood Q-tips, but not for cleaning heads…
Boy do I remember doing that phew..DVD players were real finicky when they came out to..
A recipe for home brew Deoxit would be great to find…
Yes it did help add to my knowledge base on this subject!
There is a YouTube video on the The Radio Shop channel at episode 40. Worth a view for anyone with switch problems.
Thanks George!
All this Happy Tube talk and I’m over here like …
https://youtu.be/-1LW_8VepGk?si=whuduRV8LYOsfylF
Yep, I’ve waited so long I forgot what I’m waiting for :(
Well back to the VACUUM tubes, where would one go today if they had no tube tester and have some tube equipment?
I have a really old unit in the basement I need to check out.
Find some guy who has a tube tested and takes mail ins? Guy might charge $2 a tube and return postage… interesting business idea…
There’s a bunch of them. Hit up any antique radio or tube-amp forum and you’ll come across a couple. I think I would want to find someone local, or at least within driving distance, because I don’t trust ANY parcel shipment & delivery service to move tubes without breaking them or shaking them into submission.
BTW, I found “George of the Tube Testers…”
https://tubesound.com/my-tube-tester-collection/
If you decide to buy a tester, try not to end up like this guy…
For 1-2 pieces of equipment, I believe I’d shop the tubes out. If you have more boatanchors than three, and intend to use them, I’d buy a tube tester and refurb it. Buy a tester that works, and know what you’re buying before you plunk down any cash. IOW do you really need that Hickok 600?
I have an Eico 667 and a Stark 9-66 (Hickok 533A with a label job) and a third one that’s just an “emission tester” (might be a Sencore Mighty Mite — I honestly don’t remember.) They each do different things, but TBH the Stark is the only one I use.
very kewl.
The woodwork is pretty, G, but I STILL don’t see that slot in bottom center for an IC-7300 with it’s nice, color touchscreen. The rest of the ‘towering inferno’ is just decoration! ;-)
You complain about the heat in Texas, yet you want to add heaters to the stack!
Dry heat for winter, mon frer – remember we has snomogeddon a couple of years back…dry heat is the answer – and a Texas Kilowatt…yeah…and when I get the bit 80 meter loop fed with twinlead…
What about that 8-point compass-rose array of Texas Rhombics I proposed to you a few years back? :-)
I talked to a fellow in Indiana on 40 meters who had a 15-element wire yagi array aimed SW at me… 10over S9. He must have several football fields of property.
Sorry, but I feel a vent coming on.
Ever since the garden dried out, I’ve been letting the goats out there to munch on the weeds and dead bean/pea plants. They haven’t made much headway. But today, upon arriving home from church, I noticed one of them under the peach tree next to the trunk. A closer look showed she was stripping the bark off the tree! I hurriedly penned the goats and inspected the tree. The bark is completely gone in a band about 1 foot high all the way around the tree. I’m about ready to shoot a goat as an example to the others.
I looked on the webby-thingy for ways to fix the damage and maybe save the tree. The only thing I found was a “bridge graft” that involves cutting new growth branches a few inches longer than the gap in the bark, shaving both ends to a fine taper and inserting them under the bark above and below the stripped area. The bad news is, one of the articles says that seldom works on peach trees. So after a couple of hours in the 98 degree heat attempting grafts, I’m thoroughly steamed.
Abq 86 degrees at 3:00 pm sun
The degrees are tolerable in the shade, but some of us can’t take the direct sun for more than a few minutes at that temperature and above. I suppose it’s the elevation thing. Hats don’t seem to help, though they are necessary for other reasons.
Here it comes… to fight the ‘Election Variant’ of COVID.
“Biden To Fund New Covid-19 Vaccine “For Everybody … Whether They’ve Gotten It Before Or Not””
https://www.zerohedge.com/political/biden-fund-new-covid-19-vaccine-everybody-whether-theyve-gotten-it-or-not
Do I hear the old Viet Nam protest resurrected? “HELL NO! We won’t go!”
The last “vaccine mandate” still required voluntary acceptance, and I didn’t volunteer. If they try forcing this one, it may well be a bridge too far, even for the sheep.
It seems that Biden is power hungry in the same way that FDR was. He’s a dangerous man, even though he seems pathetic.
George, this is completely on topic.
and On the topic of, “waiting for Goddot.”
i walked in the house and that movie Heart of Stone was playing on the Netflix, -> staring that smoking hot brunette, Gal Godot. after my last comment, as i walked in the house, gal gadot in the movie flashes the 9 of hearts on the screen which has a big stag in the middle of the card.
hmmmmm.
Godot finally showed up.
im a big fan of Ms. Godot. she is definently marriage material. the girl of my dreams.
holy Cow! i didnt know Gal Godot is the former Ms Israel!
merkabah refrences and Gal Godot being Ms Israel.
lol
fuck it. lets get married.
hahah
fuck i hit the powerball last night. hahaha. i dont know how much i won but i bought 16 tickets with the number 5 for the powerball on friday morning. hahahah
im going to go check my tickets now. even if i only got the powerball on all of them that $12.00 a hit.
whooh!
well, i didnt get all 6 numbers on the powerball last night but i did pretty good.
i spose i will see what that stag says tommorow night.
im going to go shave my balls and put on my super man underoos, in case Ms Godot graces with her presence.
hahah.
well….. i was drunk the day my mom got out of prison. and i went.. to pick her up! in the raaaaain! but before i could get to the station in my Pickkkkk uuuuuup truck! she got runed over by a damned old traaaaainnn!
hahaa. the perfect country and western song. my favorite country song ever.
que ~ You never even called me by my name ~
https://youtu.be/nOAz9tMYs1Y?si=bOsLKFo0pGFco1zm
David Alan Coe
“In addition to a totally smoking hot pharmacist (long brunette hair, yoga practitioner, too) they also had a tube checker. Sadly, we spent most of our time there with the tube checker.”
‘Must be nice. I had the stereotypical bald headed dude with pince-nez glasses, shar-pei wrinkles, and an endlessly large receding forehead. I think he was the inspiration for the pharmacists that appeared in Disney and WB cartoons in the 1930s
The tube checker must’ve had 125 sockets.
‘Seemed like every drugstore and hardware store had one. Even a couple of the used furniture stores had ’em. Funny, I don’t remember any of the electronics stores having one (at least they didn’t have one which was publicly accessible.) My LET (Licensed Electronics Technician) brother had a portable, as did the LET next door and the one a block away (none of which was I ever allowed to use.) I learned how to use the one at the drug store when I was about seven or eight, because that’s when I began to learn my way around amps and TVs, and when Mom gave me her (1930s vintage) floor-standing Zenith radio…
Check out TV-7/U Vacuum Tube Tester Military/Army on eBay!
https://www.ebay.com/itm/355001209916?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=nLwq8lxsQLe&sssrc=4429486&ssuid=r1uQOulkRHC&var=&widget_ver=artemis&media=EMAIL
These are good, I have one, and seem to have risen greatly in price!
The army surplus center has an enlarger..when new..that unit cost more than a hundred grand..I can drag it out for fifty…wife would shoot me.. but dam its tempting..
My best friend’s father worked as a part time pharmacist at Owen’s at the time. I remember the tube tester but I went there for the comic books and candy! Could hardly wait for the next Superman comic when he went to “Bizarro World”. If there were no new comics there was always the library across the street. Tomboy and the dime store had a bigger selection of candy.
The Smartees bin – and by weight!
A library that I worked at! Fiction was on the south wall – I shelved ;em all! Major went to O’Dea… South of the librarywhere long before that was a Safeway store in what would later become variously parking lot, a shucks store, a plumbing shop and more.