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Components and Circuits | Forum profile
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Forum profile page for Components and Circuits on http://www.vintage-radio.net.
This report page is the aggregated overview from a single forum: Components and Circuits, located on the Message Board at http://www.vintage-radio.net.
This forum profile page summarizes the general forum statistics such as: Users Activity, Forum Activity, and Top Authors, which are reported in either a table or graph below for a given reporting time period.
Additional forum profile information for "Components and Circuits" on the Message Board at http://www.vintage-radio.net is also shown in the following ways:
1) Latest Active Threads
2) Hot Threads for Last Week
Warning: These statistics are generated using 'best efforts' and can experience delays and reporting errors at times. Please note that such statistics do not constitute a forum's popularity and/or exact posting volumes at any given reporting period.
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Posting activity on Components and Circuits:
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1,018
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Components and Circuits Posting activity graph:
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Top authors during last week:
user's latest post:
Frequency counter
Published (2009-12-22 21:03:00)
Normal TTL decade counters (the likely logic family to partner a nixie?) can go up to about 20MHz. I think some went to 50MHz. DTL would go to 5MHz?
user's latest post:
Electrolytic Capacitor leakage
Published (2009-12-24 22:02:00)
My experience with the capacitor in post #3 : The other section refuses to re-form. The lowest current flow there was still 0.15mA, even after 3 hours.
user's latest post:
Am I testing this voltage...
Published (2009-12-22 00:55:00)
The 50Hz/60Hz issue is unlikely to be a problem unless the transformer is being run close to its ratings, which is unlikely in a piece of professional test equipment. Paul
user's latest post:
Reforming Waxy capacitors
Published (2009-12-22 10:57:00)
as has been mentioned, Aluminium Is indeed a very reactive metal, but it Also has the property of being amphoteric. so I suspect that the "fault" lies within the paper itself, or rather the process used to make this paper. often acid or bases are used in the manufacture of paper, and even if Perfectly neutralised (very hard to do!) it will still leave salts of this neutralisation. this isn`t really problem up to this point,...
user's latest post:
Am I testing this voltage...
Published (2009-12-23 15:44:00)
Many thanks for this info. Brian, believe it or not the car broke down again (after repairs!) but I'll bear you in mind once the Fluke arrives. Many thanks.
user's latest post:
Electrolytic Capacitor leakage
Published (2009-12-24 11:19:00)
There has been loads of discussions on this subject. This tread may be worth a read: http://www.vintage-radio.net/forum/s...ad.php?t=34337 The key issue is to keep the current right down to avoid any heating and gas generation. My experience is that electrolytics behave like zener diodes and as they reform the breakdown voltage goes up. So feeding a low current and monitoring the voltage is a good way to go. Another observation that I have...
user's latest post:
EL33 bias
Published (2009-12-23 18:26:00)
I see what you mean. The two cathode resistors are tapped at their junction and connected to the grid leak. The 150R sits closest to the cathode
user's latest post:
Capacitor questions for high...
Published (2009-12-22 10:11:00)
Hello Thanks for that. I know. It is a complex issue because there are many factors involved. The cap is not used out of spec though. I am leaning toward trying ceramic X2 but today I discovered that they will not fit in:-(. I will try and spec a different manufacturer for the next manufacturing batch. I will also test some non-X rated polypropylene caps from Vishay. Needless to say, the test always show that it will be just fine Kind regards...
user's latest post:
Am I testing this voltage...
Published (2009-12-23 05:02:00)
...and 'T' prefixed fuses are 'slow-blow' ('F' prefix = 'quick blow') So, a 1/16A slow-blow fuse = T63mA .
user's latest post:
Frequency counter
Published (2009-12-22 21:03:00)
Quote: Originally Posted by Herald1360 If it's old with nixies, it may not go very high in frequency either, though even a 1MHz top end would be useable for broadcast LW/MW receiver alignment purposes. There's an exception to every rule - my HP 5245L has a row of 8 nixie tubes and is good to 500MHz with its plug-in frequency converter...
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Latest active threads on Components and Circuits::
Started 3 days, 19 hours ago (2009-12-23 20:22:00)
by GMB
If you download the manual for the military capacitor reformer from my web site you will find it gives a table of leakage currents.
http://home.btconnect.com/gmb/ReformerNo1.pdf
Started 2 weeks, 2 days ago (2009-12-11 00:00:00)
by Peter.N.
Depends primaraly on how good your signal is. If you live fairly near a transmitter a ribbon aerial is likely all you need, if you are getting any fading or multipath distortion then a proper beam would give an improvement. Outside is better but again it depends on your signal.
Peter
Started 1 week, 3 days ago (2009-12-16 20:34:00)
by Biggles
I would agree, removing the cap increases negative feedback, reducing gain and in theory makes the circuit more linear. Perhaps the notion that it sounds better has other influences which alter the response of the circuit, making it more pleasing on the ear by slightly altering the tone i.e boosting bass at a particular frequency. It could depend on speaker, output transformer or cabinet ...
Started 1 month ago (2009-11-24 09:18:00)
by Mike Phelan
Put the cap back - VHF front-end caps are critical in regard to temperature compensation.
Replacing just one cap won't fix it; there are several stages, plus tracking and padding to produce a real dog's breakfast if you alter any of them!
What sort of set is it?
There might be a mechanical solution: can the tuning gang rotate any more towards the "open" side, and/or can the mixer and ...
Started 3 days, 5 hours ago (2009-12-24 11:12:00)
by GrimJosef
OK, since detailed info seems to be in short supply I spent a couple of hours on some experiments yesterday.
I suspended the test resistor in free air (see pic - the cardboard screen which hides a confusing mess behind it was only there for the photo, not for the tests themselves). I measured the temperature using a small thermocouple in contact with the top surface of the resistor - ...
Started 4 days, 7 hours ago (2009-12-23 08:26:00)
by Station X
http://www.r-type.org/exhib/aad0112.htm
The combined anode and screen currents of an EL33 add up to 40mA. The recommended gid bias is 6V.
Using ohms law R=V/I 6/0.040=150 ohms.
Started 5 days, 21 hours ago (2009-12-21 18:35:00)
by Station X
Looks like you've got the meter set to DC Volts (V------). It should be set to AC Volts. (V~)
The device is just a transformer, possibly an autotransformer.
Started 5 days, 20 hours ago (2009-12-21 19:17:00)
by cmjones01
If you've got a signal, and you want to know its frequency, you connect it to your frequency counter. There are other time-related measurements a counter can be used for, but that's the main thing.
I've most recently used mine to check the 1Mhz and 37.5Mhz signals inside a Racal RA17, I think.
Started 6 days, 21 hours ago (2009-12-20 19:08:00)
by Barry Lloyd
Most interesting. Very encouraging results! I once tried frying a waxed-paper capacitor in candle wax, hoping to get it above 100C and drive off the moisture, the wax then sealing it. I monitored the leakage current while I was doing this: the leakage increased and, assuming that my process was making matters worse, I gave up on on it. In view of your results, maybe what I was seeing was the ...
Started 5 days, 15 hours ago (2009-12-22 00:22:00)
by berntd1
Capacitor questions for high voltage / AC
Hello all,
Is there a general concensus on which type of capacitors (modern) are most suitable for mains applications but low current?
(100nF - 330nF)
My expsrinece has shown that X2 is no good. They go short circuit eventually.
I think they are not that suitable for low ...
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Hot threads for last week on Components and Circuits::
Started 5 days, 21 hours ago (2009-12-21 18:35:00)
by Station X
Looks like you've got the meter set to DC Volts (V------). It should be set to AC Volts. (V~)
The device is just a transformer, possibly an autotransformer.
Started 6 days, 21 hours ago (2009-12-20 19:08:00)
by Barry Lloyd
Most interesting. Very encouraging results! I once tried frying a waxed-paper capacitor in candle wax, hoping to get it above 100C and drive off the moisture, the wax then sealing it. I monitored the leakage current while I was doing this: the leakage increased and, assuming that my process was making matters worse, I gave up on on it. In view of your results, maybe what I was seeing was the ...
Started 2 weeks, 2 days ago (2009-12-11 00:00:00)
by Peter.N.
Depends primaraly on how good your signal is. If you live fairly near a transmitter a ribbon aerial is likely all you need, if you are getting any fading or multipath distortion then a proper beam would give an improvement. Outside is better but again it depends on your signal.
Peter
Started 1 week ago (2009-12-20 09:25:00)
by David Tilley
Why not just use a pair of germanium diodes instead of the EBC33? Less heater current for one thing,
Started 4 days, 7 hours ago (2009-12-23 08:26:00)
by Station X
http://www.r-type.org/exhib/aad0112.htm
The combined anode and screen currents of an EL33 add up to 40mA. The recommended gid bias is 6V.
Using ohms law R=V/I 6/0.040=150 ohms.
Started 5 days, 15 hours ago (2009-12-22 00:22:00)
by berntd1
Capacitor questions for high voltage / AC
Hello all,
Is there a general concensus on which type of capacitors (modern) are most suitable for mains applications but low current?
(100nF - 330nF)
My expsrinece has shown that X2 is no good. They go short circuit eventually.
I think they are not that suitable for low ...
Started 6 days, 23 hours ago (2009-12-20 16:17:00)
by geofy
Try contacting them here;
http://www.partridgeelectronics.co.uk/enquiryform. htm
Not sure if this is any help.
http://www.campusupg.ro/scheme/carti...0Amplifier. pdf
Started 5 days, 20 hours ago (2009-12-21 19:17:00)
by cmjones01
If you've got a signal, and you want to know its frequency, you connect it to your frequency counter. There are other time-related measurements a counter can be used for, but that's the main thing.
I've most recently used mine to check the 1Mhz and 37.5Mhz signals inside a Racal RA17, I think.
Started 5 days, 18 hours ago (2009-12-21 21:56:00)
by paulsherwin
They're probably private manufacturer codes. You should be able to work out the basic parameters (NPN/PNP etc) using a transistor tester or even a DMM, but you may never find any detailed info. If either is PNP it might be worth trying them out as AF11x substitutes.
As you say, the 2SC1815 appears to be a BC108 class transistor, though my Towers doesn't list any equivalents.
Paul
Started 3 days, 19 hours ago (2009-12-23 20:22:00)
by GMB
If you download the manual for the military capacitor reformer from my web site you will find it gives a table of leakage currents.
http://home.btconnect.com/gmb/ReformerNo1.pdf
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