Reminds me of being at college learning electronics.
We all had to build up a small amplifier circuit.
Out of 15 about 5 had their electrolytics bounce of the ceiling !
A big cheer went up each time.
So it wasn’t a faulty amplifier after all. Where are you doing to get another ‘matched pair’ these days?
Here's a matched quad of 6P14P. They are used but test good and I've bought used tubes many times - they were fine.
https://www.ebay.ca/itm/154941903968
Or buy 50 and match yourself... https://www.ebay.ca/itm/254808534546
https://www.ebay.ca/itm/154941903968
Or buy 50 and match yourself... https://www.ebay.ca/itm/254808534546
Not an exotic failure ...
I've been building amps and things for quite a few years now with just the 'usual' number of mistakes (!) but it's the first time I've actually reversed the polarity of the power supply electrolytic caps - silly mistake - extremely irritating and such a waste in this time of vanishing available components.
If you don't get them, you get a refund though. That's the beauty of using Paypal to buy from eBay. You have three layers of buyer protection 🙂
Blew the output stage of my Heathkit signal generator ... too much output at 100kHz and a wire wound resistor that went capacitive and shorted out. Now have to figure out how to get it rebuilt.
It should be pretty easy to find the schematics/instructions as Heathkit were just that - kits that you DIY.
I have the schematic, and have tried to repair it once already. Purchased exact replacement numbered button transistors which turned out to be counterfeit (very low beta compared to the original beta=100) and below spec. I have found generic spec replacements and will try again. I hope it is just the push-pull pair of blown output transistors. Is there anything else I should check?
I have another Russian tube that limps along in its place; works better than nothing but not as nice as the new one was supposed to turn out. Will still let me continue "development" to see why the Fisher-branded inanimate object is giving me such a hard time.
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Why settle for orange when you can get to white!
Many years ago I decided to visit the tube I learned on as a kid in the 60's, the 6BQ6. Available in GT and GA (bigger) form, these and their bigger brother the 6DQ6 were the common tube in dead B&W TV sets. If you solder a plate cap to pin 3 of the tube socket they are pin compatible with the usual audio tubes. Note that just because the pin out is correct don't assume that they will work in your amp or anything else without modification. I did not understand things like bias or impedance as a kid, so I didn't understand why the big tubes (6DQ6's) just got hot, but didn't make much power. A 6BQ6GA could however make about 10 watts in a DIY SE guitar amp.
This got me to wonder how much power they could make in a SSE board with a separate power supply on G1, G2 and the plate. I determined that about 30 watts can be obtained from a single tube in SE for about 10 minutes. This is what you do with the ugliest tubes when you get a bunch of them for about 75 cents each.
If you have good T-mobile coverage in your area look into Mint Mobile. I use an old Motorola Android phone on Mint for a second phone for data and hot-spot use. It's $15 per month for 4GB of data and all you can yack or text. I vote for death by microwave oven....just don't use a nice oven, a flaming phone will scar it for life. Put the phone on a paper plate or something to hold it about 1.25 inches (1/4 wavelength at 2.45 GHz) above the floor of the oven for maximum fireworks. An SOS pad makes for a huge plasma ball. Some old tubes met their death in the microwave too. C4 is cool, but it's use tends to attract law enforcement.
Attachments
Sorry, my lame vote for the proper method of destruction for an Apple product. Won't happen again.
Since I was set up in the outdoor flea market and watching my tables by myself, I did not get to see much beyond my viewpoint. I did get to wander the flea market some before opening and after closing, but my flea market vendor ticket did not allow me access to the buildings outside the normal business hours. In previous years I could "borrow" a commercial vendor ticket from Stan at ESRC, but that's not an option now, so I have no info about the ham equipment inside the buildings. There are several YouTube videos with complete walkthroughs including some of the flea market.
My personal flea market experience started out with an event fitting this thread. Thursday was setup day. The hamfest was not open to the public but vendors had most of the day to set up their stuff. I set up my tables, a pop up canopy that I have used for years, placed several heavy sales items on the tables, and covered everything with tarps. Thursday is also a popular day for vendor to vendor sales. The guy next to me in the flea market was also selling tubes and other vintage audio and electronics stuff kept returning to his tables with acquisitions. I took the last hour of the day to wander the flea market, but didn't buy anything. I left for my hotel about 15 miles to the east at closing time. I was awakened in the middle of the night by hail hitting the hotel window and severe storms.
I got to my flea market spot before dawn Friday morning to find my canopy destroyed and a couple tables flipped over. There were several other flea market vendors in the same situation. Friday is usually the best day in terms of selling stuff, but I spent most of the morning recovering from the mess. I never even got my generator running or any of my test equipment powered up. Despite the mess, I still sold some tubes, transformers, old radios, and other stuff that I would never use. From my perspective it did look like there was a good crowd and lots of money changing hands. My only purchase was $6 worth of ice cream "home made" on site.
I got to my site before dawn on Saturday and had everything set up before opening. The usual crowd surge as the gates opened was strong and lasted until well after noon. I did see a lot of stuff changing hands and a good bit of "equipment" being carried out to the parking lot. The oddest "ham radio related equipment" that I saw change hands at the hamfest was an accordion and a mint looking grill for a 1969 Camaro. A few diyAudio members stopped by to chat. One group picture was taken and it is in post #200 here:
https://www.diyaudio.com/community/threads/anyone-going-to-the-dayton-hamfest.165790/page-10
Around 3 PM Saturday, a voice came over the PA system advising the outdoor flea market vendors that a strong storm system was approaching the area and would arrive in 20 to 30 minutes. the storm contained high winds and rain, small hail, and lots of cloud to ground lightning. Radar on my phone showed a lot of ugly coming our way. Vendors were urged to lower or remove all antennas as some people in the flea market had erected towers, secure all belongings, and take shelter in a vehicle or building. Most took this as an exit call. I packed everything in the van and decided to get wet and go shopping for bargains. I wandered the flea market in the mild rain for about an hour and a half, but everybody had left or was leaving. I did not buy anything. The strong storms never materialized. I left about 5 PM and met the strong storm on the way to my hotel. It would not have been fun to go through that in a large flat field with lots of antennas for lightning rods. I did not drive through any hail, but the parking lot of the hotel was 4 inches deep in rain water with plenty of ice cubes floating in it.
Sunday morning there were only about 10 to 20 % of the vendors remaining in the flea market. There were lots of damaged tents and canopies, so the storm obviously found the fairgrounds after I left. The general public gets into the hamfest for free on Sunday and large crowds are expected at open, and around noon. Neither materialized, but there was a slow steady flow of people.
All in all I converted several hundred pounds of stuff that I'll never use into a few hundred dollars to buy stuff that gets blown up or used in the quest for music reproduction and generation. My only non edible purchase was $10 worth of pin headers that will go into a DIY music synthesizer module. I'll do it again next year.
Thanks for great detailed report George. Sounds like quite a weather event. Hopefully better luck next year.
I have been going to the Dayton hamfest every year since 2010 and off and on before that. I can only remember one year when there wasn't some ugly weather on at least one of the 4 days. One must expect some kind of ugly weather and some extreme temperature changes at Dayton because it will usually happen. This time we had 91 degrees on Saturday before the storm and 56 degrees on Sunday when I got there. That's not a big deal, but one year it was 20 degrees on Friday morning and in the mid 80's Friday afternoon. The only time that I ever got cold enough to leave a hamfest was in Orlando about 15 years ago. I don't know the numbers but the blue snowflake (bad weather icon) on my old Volvo wagon was illuminated. The only other time I saw it lit was when it was actually snowing in Ohio.
Now; let me go fire up the power supply and destroy something (always a possibility).....back to our regularly scheduled program...
I admire your one-pointedness to just get rid of stuff - and not pick up more to take home. The trip sounds like quite an adventure, despite the battles with Mother Nature!
The problem is that we DON’T have good T-mobile coverage in the area anymore, and it gets worse by the hour as they de-commission all the old frequencies that our old phones support. What they want is for everyone to buy a new $1000 phone to use 5G (By turning off 4G, 3G and Edge). We don’t do all the video crap on our phones anymore, but you can’t make a call if there’s “no data”. Now it will be a cheap phone you can talk on that support the new bands, and only cost $100 if it gets chewed up by a dog. End of phone problems, until the 6G or 7G roll out.
We do have an old microwave that works when it wants to (the power relay sometimes refuses to latch and you have to keep your finger on the button to heat up a sandwich). Maybe three birds with one stone.
