AliExpress has quite a few options—this one is $4.99 delivered, the knob is a buck more.

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Several of the listings appear to be new old stock, some tarnish on brass and plated parts.

I had some really big ones long time ago, from old radios. It's too bad I threw a lot of that stuff out over the years.

 

AliExpress has quite a few options—this one is $4.99 delivered, the knob is a buck more.

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I used to by new, complete AM radios for that much and later when every radio in the U.S. had to tune both AM and FM I could buy a complete new AM/FM radio for that much.

 

I used to by new, complete AM radios for that much and later when every radio in the U.S. had to tune both AM and FM I could buy a complete new AM/FM radio for that much.

Yes, and you can still do that—but they don't use variable caps.

My reply was mostly to:

I remember them as very cheap, the plastic ones for transistor radios were under $5.00, I don't think they exist anymore.

 

I have long regretted all those old radios I threw away without keeping their tuning cap. About the same with transformers... But then I'd have even more junk than I already have crammed in about the house. There is a very strong hoarder gene in our family as it is.

 

I used to by new, complete AM radios for that much and later when every radio in the U.S. had to tune both AM and FM I could buy a complete new AM/FM radio for that much.

I notice those caps do not list their variable range, for reasons I'm not entirely sure of the 10pf - 365pf for AM was a standard.

 

Hello,

I have seen AM tuning capacitors upto almost 500 pF..
See this page:
https://stormwise.com/page3.htm

Bertus

 

I notice those caps do not list their variable range, for reasons I'm not entirely sure of the 10pf - 365pf for AM was a standard.

As I recall, tuning caps (not counting trimmers) don't quite get up to a 10:1 capacitance ratio. More like 35pf- 365pf from memory.

 

As I recall, tuning caps (not counting trimmers) don't quite get up to a 10:1 capacitance ratio. More like 35pf- 365pf from memory.

To tune the entire AM band, you need to vary a tank circuit from 530 to 2700 KHz. This is a ratio of 3.2. But the frequency is proportional to the square root of the capacitance, so the capacitance ratio needs to be the square of that, or 10.3.

365:35 is 10.4.

 

Actually the band is 530KHz to1600KHz in the USA I spent around 30 minutes researching it.

 

So I was reviewing an old thread where I had to order parts from China just for the heck of it I reviewed those orders and went to see if I can get those parts from Amazon. The results kind of surprised me. The parts in question were the LM334 small current regulator LM334 and the LM4041 shunt regulator.

When did Amazon become a hard to find parts seller?

 

So I was reviewing an old thread where I had to order parts from China just for the heck of it I reviewed those orders and went to see if I can get those parts from Amazon. The results kind of surprised me. The parts in question were the LM334 small current regulator LM334 and the LM4041 shunt regulator.

When did Amazon become a hard to find parts seller?

When they started making money from it.

 

I started buying parts from china when I found out that the same parts on Amazon were cheaper when buying directly from china and cutting Amazon out as the middle man. That was several years ago. The same parts are also available from china on eBay but cheaper on Amazon if you have their Prime membership and don't have shipping charges included. But, even with tariffs and increased shipping costs from china, they are still cheaper buying from AliX if you want cheap and probably "generic" cloned/copied/counterfeit parts that may or may not be even close to their actual specs. I bought some MosFets from AliX that were actually NPN BJTs even though they were marked with a counterfeit makers logo and part number for a Fet. So, beware of what you buy from AliX. Especially if it is a hard-to-find part!

 

I'm feeling kind of down right now, my birthday was last week and I spent the weekend spewing from both ends (no fun at all). I've been trying to get traction on several electronic projects with very little success it seems. Oh well, I just keep plugging at it. It's what I do. I'm feeling less and less relevant as time goes on tends to make me very depressed even more so now that I am better.

 

Oh well, I just keep plugging at it. It's what I do. I'm feeling less and less relevant as time goes on tends to make me very depressed even more so now that I am better.

If I am unmistaken, as we age past a certain point, we find ourselves at the top of a hill and there is nowhere to go but down.Then maybe a exciting up-swing further into future.

 

@Wendy - I'm fighting the same battle, though probably to a lesser degree than you are (for now). Intellectually, I realized about twenty years ago that I had reached an age where, no matter what I might succeed in doing as far as getting into shape (something that has yet to happen), that I would simply never be able to do many of the things that I had always dreamed of doing. But I don't think I really believed it. As I now try to get into the world of practical handgun competition, I have finally been forced to actually believe it. I still hope to do the best I can and make whatever progress I can, but I have no illusions that I can get much better than I am right now and will likely start going downhill in the next few years. Not surprisingly, confronting that reality has forced be to face the bigger reality that I am quickly becoming an old man and the number of years of anything resembling an active lifestyle are becoming decidedly limited. So, while that is definitely disheartening and leaves me with bleak moments, I'm focusing on enjoying what I can, to the degree I can, while I can.

 

Not surprisingly, confronting that reality has forced be to face the bigger reality that I am quickly becoming an old man and the number of years of anything resembling an active lifestyle are becoming decidedly limited. So, while that is definitely disheartening and leaves me with bleak moments, I'm focusing on enjoying what I can, to the degree I can, while I can.

Keep at it.

11 years ago (at age 62), I took up ballroom dancing, something for which I had no prior experience or ability to apply. For about 2 years I made decent progress, getting me through the beginner levels (a young person could do that in about 3 months.) Then came the plateau. Progress was slow to negative for years. Then, somehow, this year (age 73) some things started clicking, and I am now again progressing through the intermediate level.

I have also taken up piano as a beginner.

I had stopped bicycling, then I got an E-bike and I am back.

It is easy to stop living without dying, and I see many people do just that. I will resist as long as I can, though the temptation is there.

Of course, @Wendy is an inspiration for overcoming limitations.

 

I am going to the ER tomorrow due to an infection in my leg which has been kind of getting out of control. I have had this ulcer on my leg since 2018, originally it was started from a DVT. Now I'm taking blood thinners up to my eyeballs. They still don't know what's causing the slow heal rate. So I will be away for a couple of days or more when I can I will let the group know more.

 

I hope they successfully put the lid on this.

 

Wendy, have yourself a happy and safe Thanksgiving and hopefully they get this figured out soon. Thoughts are with you. Please keep us up on progress.

Ron

 

It's interesting to me how times change (or GAWD I'm getting old!). Now and then I go on a parts hunt (or can I build old projects?)

My latest was radios,as in crystal and other types. Anyone remember the 8.8pf-365pf variables for crystal radios and other projects? I remember them as very cheap, the plastic ones for transistor radios were under $5.00, I don't think they exist anymore. Their large air gaped cousins go go $35 -$45.00, depending how long your willing to wait. I have no intention of getting these parts. When I was a teen I thought there was something magical about radio & TV my preteens I watched B&W because color TVs weren't made yet. I used to spend hours listening to our short wave at night. Good Memories. Around the time I started on transmitters (AKA RF oscillators) my Dad developed a new order when his TV reception went south."Turn it off!".

You were right, there truly is something magical about radio. its so taken for granted these days. Few people - even people here - ever stop to just contemplate the marvel of communication over great distances without wires. Radios, especially "short wave" really brought this home to me as a kid.

As a kid we had radios and at one time a "radiogram", the sound was always rich, no doubt due to the enclosed wooden cabinet.

I recall my "hobby" for a while, was looking into the vented back covers, in the evening with the lights off I could see these dim orange glowing glass things, secretly hidden away from the users.

Here's some history, skip the first minute, this link does that for you: