Forums :: NEW! Web Resources :: Features :: Photo Gallery :: Vintage Radio Shows :: Archives
Support This Site: Contributors :: Advertise


It is currently Nov Tue 30, 2021 7:44 pm


All times are UTC [ DST ]





Post New Topic Post Reply  [ 17 posts ] 
Author Message
 Post subject: Bought a capacitor tester at a hamfest for 5 dollars
PostPosted: Sep Tue 14, 2021 1:36 pm 
Member
User avatar

Joined: Feb Sat 28, 2015 8:37 pm
Posts: 759
Location: Walker, MI
I have always just changed the caps and tossed them as it's of course common belief that the caps are bad. Was at a Hamfest this past weekend and found a table that had an old heathkit cap tester and a Heatkit RF signal generator. Got them both for $10 so I figured what the heck. ..
Pullled the capacitor tester apart last night and replaced the caps (one was popped) and cleaned the wafers and tubes pins and fired it up. At first one of the tubess didn't light up, but more cleaning and it lit up. It's the IT-11 model number and seemes to work fine. I tested new caps from Sal and old caps from the unit and, yeah the common belief is true, all the caps leak at much lower voltage than rated and could not get the eye tubes to open on the 40uF caps above around 100v (rated to 350). I think I would have really enjoyed this thing, but I made the mistake to look on ebay and see how much it's worth. Yikes, I can't understand why they go for such big bucks. Seems like $200-$300 is the going rate, and now that this one has been recapped (a half hour job lol) and is working, I bet it would go for the upper amount. I really had no idea that they where going for that much. So not sure if I'll cash out so to speak or just hang onto it. It's kinda fun to see how bad these old caps are, but on the other hand, what's the point? If there was an odd cap that was good, I am certainly not going to reinstall it. This device seems to be a soltuion to a problem that is not needed. I am not even sure I would test old caps before tossing them for most projects. I guess you can use it to measure values, but I am not sure I would ever do that. Pretty cool circuit and it's always fun playing with a majic eye tube.


Top
 Profile  
 
 Post subject: Re: Bought a capacitor tester at a hamfest for 5 dollars
PostPosted: Sep Tue 14, 2021 1:57 pm 
Member
User avatar

Joined: Jan Tue 31, 2012 1:55 am
Posts: 18661
Location: Mountains of Mourne. Ireland.
Yikes, I can't understand why they go for such big bucks.

Guitarists and audiof00ls have driven up the price of Heathkit capacitor testers years ago.


Top
 Profile  
 
 Post subject: Re: Bought a capacitor tester at a hamfest for 5 dollars
PostPosted: Sep Tue 14, 2021 2:09 pm 
Member
User avatar

Joined: Jun Wed 08, 2011 2:33 am
Posts: 12346
Location: Ohio 45177
Nice to be able to test NEW caps from time to time. Especially NOS ones out of your stash. If you have none and just buy new caps as needed, then you can place your trust in the sellers and assume you are not a lottery winner and will not get that one in a million. I have accumulated lots of capacitors old tube radios.

_________________
Reddy Kilowatt says; You smell smoke? Sorry about that!


Top
 Profile  
 
 Post subject: Re: Bought a capacitor tester at a hamfest for 5 dollars
PostPosted: Sep Tue 14, 2021 2:14 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 11102
Location: 13 Critchley Avenue, PO Box 36, Monteith Ont, P0K 1P0
k8cca wrote:
So not sure if I'll cash out so to speak or just hang onto it. It's kinda fun to see how bad these old caps are, but on the other hand, what's the point?

Exactly.

If you are an experimenter, then having the test equipment for those purposes is great! That's why I have a GR bridge for testing LCR. However, a cap leakage tester can be made for very few dollars .... a variable voltage supply (which any self respecting experimenter should already have), a ma meter (same) and some jumper leads with alligator clips, so ......

Cash out while the getting is good !!


Top
 Profile  
 
 Post subject: Re: Bought a capacitor tester at a hamfest for 5 dollars
PostPosted: Sep Tue 14, 2021 2:15 pm 
Moderator

Joined: Jan Thu 01, 1970 1:00 am
Posts: 18899
Location: Utica, NY 13502 (USA)
I'm told that a cap tester is essential to those who worship Black Beauties to be sure they have enough leakage to "sound right". For entertainment, I sometimes test the old caps that I've replaced and usually find that 100% of them are bad.

In my experience this point in time, any NOS paper or electrolytic cap is likely to be leaky or will shortly become leaky when pressed into service.

Dave


Top
 Profile  
 
 Post subject: Re: Bought a capacitor tester at a hamfest for 5 dollars
PostPosted: Sep Tue 14, 2021 2:22 pm 
Member
User avatar

Joined: Feb Sat 28, 2015 8:37 pm
Posts: 759
Location: Walker, MI
I hear ya, cash out while the cashing is good. I don't really experiment, so I am really not sure that I need it. I have always wanted a calibrated RF signal generator like the HP 8656B, but am to cheap to spend that money as I have a B&K soslid state signal generator (can't remember the number). If I can turn my $5 into $300 via ebay them that would take the sting out of one these bad boys. How much does ebay steal these days? I have good rating as I used to sell there back 15 years ago, but really have no idea on fees these days.


eta I have a pile of BB that I saved to sell on ebay, but have never gotten around to it. Of course who cares on the fees when selling something that should be thrown away, but I digress. :roll:


Top
 Profile  
 
 Post subject: Re: Bought a capacitor tester at a hamfest for 5 dollars
PostPosted: Sep Tue 14, 2021 2:39 pm 
Member
User avatar

Joined: Jan Tue 31, 2012 1:55 am
Posts: 18661
Location: Mountains of Mourne. Ireland.
eBay is a legitimate business, they do not steal anything.
If you don't like their platform maybe you should go elsewhere. lol

https://www.thebalancesmb.com/what-to-k ... ll-1140371


Attachments:
fees.png
fees.png [ 56.2 KiB | Viewed 870 times ]
Top
 Profile  
 
 Post subject: Re: Bought a capacitor tester at a hamfest for 5 dollars
PostPosted: Sep Tue 14, 2021 3:00 pm 
Member

Joined: May Thu 14, 2015 4:15 pm
Posts: 3599
Location: Dallas, TX
k8cca wrote:
If I can turn my $5 into $300 via ebay them that would take the sting out of one these bad boys.

To be accurate, you also spent on the new parts as well as your labor. Then there is the time and effort selling it on ebay. So the profit isn't quite that good.

_________________
Tim
It's not the Destination, It's the Journey.


Top
 Profile  
 
 Post subject: Re: Bought a capacitor tester at a hamfest for 5 dollars
PostPosted: Sep Tue 14, 2021 11:41 pm 
Member

Joined: Nov Wed 27, 2013 5:59 am
Posts: 867
Location: Metzger Oregon
This model is useful because it applies high voltage to the cap under test, and can be used to reform them, unlike many more basic testers. That's part of the reason for the higher value.


Top
 Profile  
 
 Post subject: Re: Bought a capacitor tester at a hamfest for 5 dollars
PostPosted: Sep Wed 15, 2021 1:53 pm 
Member

Joined: Jun Fri 19, 2009 6:34 pm
Posts: 11145
Location: Long Island NY
You got a real gift from somebody there who either did not know or did not care what they had. When things like that fall into my lap I tend to keep them in appreciation of my good fortune; it seems to encourage more good luck. If you really don't going to use it, then I'd also suggest selling it before the bubble bursts. But I'd check the "completed listings" first before counting your profits; most IT-11s currently selling online seem to be going for around $150 to $200 unless they are NIB unbuilt kits or overhauled and calibrated by self-appointed gurus.

The big advantage of the IT-11 and the IT-28 (an updated version) is, they are amplified bridges. The sensitivity to measure low capacitance values and low leakage currents comes from an amplifier tube, not from putting higher voltages across the capacitor being tested. This makes them very usable on the low voltage electrolytics found in solid state gear while retaining the ability to test higher voltage caps in tube gear. It gave much of the functionality of a Sprague TO-6A at about 1/10th the price.

Neither Heathkit nor Eico ever made a capacitor tester intended to be used for reforming old capacitors. The fact that lots of people do so explains why many instruments end up "as is, don't know how to test" on eekBay with smoked transformers and resistors. It says "Capacitor Tester" for a reason. You test the cap, then you move on. If you feel a capacitor needs reforming, a variable voltage bench supply should be used instead.

I suspect much of the interest in these instruments today springs from electric guitar affectionados looking for usable vintage tone caps. Since there are only millivolts of audio signal involved, DC leakage at 600 volts is irrelevant. The IT-11 can tell you what the leakage is at three volts which is more than enough for a guitar tone control.

_________________
"Hell, there are no rules here--we're trying to accomplish something!"

Thomas A. Edison


Top
 Profile  
 
 Post subject: Re: Bought a capacitor tester at a hamfest for 5 dollars
PostPosted: Sep Wed 15, 2021 2:51 pm 
Member
User avatar

Joined: Feb Sat 28, 2015 8:37 pm
Posts: 759
Location: Walker, MI
Yeah I have not done anything with it at this point except get it up and running. In fact spent last night tearing down an 800CC 2 stroke snowmobile engine in preparation of the upcoming season. I am not in a big hurry to sell it. It's a pretty cool device. My next project is to get my Collins KWM-2A up and running that I bought this past summer at another swap. It's former chesse loving inhabitants made quite the mess. Again, another deal that I could not pass up.


Top
 Profile  
 
 Post subject: Re: Bought a capacitor tester at a hamfest for 5 dollars
PostPosted: Sep Wed 15, 2021 9:32 pm 
Member
User avatar

Joined: Jul Mon 08, 2013 2:48 pm
Posts: 815
Clean it, check it, an then put it for sale on Ebay. Some people (audiophiles and guitar amps tweakers) are paying insane prices for these and only use them to check leakage and for reforming electrolytic caps (which the IT-11 was not made for). Nobody use it for its bridge (meter) features.
For 30 $ (or likely much less if you dig into your old junk parts boxes ) you can build a better capacitor leakage tester/reformer and for a little more you can buy an extra small digital capacitor meter (nobody today measure resistors or capacitors values using the old weathstone balancing bridge method, which is slow, tedious and less accurate)
And if you don't want to build it yourself, the LEADER (Lafayette, Olson,...) TE-46 CR Analyzer does about the same (and also includes a calibrated leakage meter, along with the green eye tube) but is much cheaper than the IT-11 because it's more common and there is no hype about it. (usually sells for 15 to 40$ at hamfests, which is the normal price for such instruments). It also goes from 3 to 600VDC in 12 stepped ranges.


Last edited by Tubologic on Sep Wed 15, 2021 10:06 pm, edited 7 times in total.

Top
 Profile  
 
 Post subject: Re: Bought a capacitor tester at a hamfest for 5 dollars
PostPosted: Sep Wed 15, 2021 9:49 pm 
Member

Joined: Feb Fri 22, 2008 3:28 am
Posts: 614
I never could figure out either why the IT-11 was going for so much $$; I have one and also got it for maybe $5 thirty years ago. I much prefer the Military ZM-11 which is a much better cap tester. Only reason I still keep the Heathkit is the ZM-11 can't do low voltage tests.


Top
 Profile  
 
 Post subject: Re: Bought a capacitor tester at a hamfest for 5 dollars
PostPosted: Sep Wed 15, 2021 9:55 pm 
Member
User avatar

Joined: Jul Mon 08, 2013 2:48 pm
Posts: 815
CurtisL wrote:
I never could figure out either why the IT-11 was going for so much $$; I have one and also got it for maybe $5 thirty years ago. I much prefer the Military ZM-11 which is a much better cap tester. Only reason I still keep the Heathkit is the ZM-11 can't do low voltage tests.


The (military) ZM-11/U and ZM-3A/U are excellent testers (extremely well build and use MUCH better quality parts than Heathkit) but are now also reaching multi-hundreds $$ prices on the big auction site.


Top
 Profile  
 
 Post subject: Re: Bought a capacitor tester at a hamfest for 5 dollars
PostPosted: Sep Thu 16, 2021 12:28 am 
Member

Joined: Feb Fri 22, 2008 3:28 am
Posts: 614
I got the ZM-11 I have at the same swap meet a few months later than the IT-11. Seems like it was $8. It had the cover but was in very rough shape, missing a couple pointer knobs, and didn't work. The IT-11 was useful in testing the MANY bad caps the ZM-11 had. Many of the caps leaked, which was odd in that thay looked like mica (6-dot) types, though all wax covered. Some were a real pain to access. I spent more $$ buying silver mica caps than I paid for the ZM-11. Has worked perfectly ever since though.


Top
 Profile  
 
 Post subject: Re: Bought a capacitor tester at a hamfest for 5 dollars
PostPosted: Sep Thu 16, 2021 2:38 am 
Member
User avatar

Joined: May Sun 10, 2020 2:55 pm
Posts: 2238
Location: SW, MI
I think it is 12.5% for electronics. That's mostly what I sell, I need to check.

_________________
only the dead fish go with the flow


Top
 Profile  
 
 Post subject: Re: Bought a capacitor tester at a hamfest for 5 dollars
PostPosted: Sep Sat 18, 2021 5:55 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 1530
Location: Auburn, AL
Don’t forget the PayPal fees or the fees fleabay charges to use their new payment system.

_________________
filling in the gaps in my education...


Top
 Profile  
 
Post New Topic Post Reply  [ 17 posts ] 

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 19 guests



Search for:
Jump to:  




































Privacy Policy :: Powered by phpBB