ELECTRONIC COMPONENTS: testing..to CONFIRM component characteristics--
ie with ferrite cores I spot test the ones I receive and for small wee orders.. I do
test them individually.
Var actor Diodes (variable capacitance diodes) I have bought bargain packs from
Dans and also I bought bulk buys on ebay. Sometimes varactors are marked only
with color bars and I test them. The MV1662s I have tested according to a table on
the NN1G site (members projects) 1 volt to MV1662 = 37 pf all the way to 450 pf
with 8 volts on the diode. --- a good wide range. See link below more data sheets
with info on this part. (I have about 500 in stock!!) IF you buy a pair of transistors
from me ..I will match them (reasonably close) as a FREE service.
ie with ferrite cores I spot test the ones I receive and for small wee orders.. I do
test them individually.
Var actor Diodes (variable capacitance diodes) I have bought bargain packs from
Dans and also I bought bulk buys on ebay. Sometimes varactors are marked only
with color bars and I test them. The MV1662s I have tested according to a table on
the NN1G site (members projects) 1 volt to MV1662 = 37 pf all the way to 450 pf
with 8 volts on the diode. --- a good wide range. See link below more data sheets
with info on this part. (I have about 500 in stock!!) IF you buy a pair of transistors
from me ..I will match them (reasonably close) as a FREE service.
A page concerning the MV1662 varactor
diodes (used as an example). My results of
testing and graphing the measurements of
this varicap diode. The test circuit seems to
work fine. My results of testing these diodes
seems to indicate they are the real McCoy.
I did a large buy of these components and
have started to sell some of them. CLICK ON
THE LINK BELOW FOR THIS TOPIC
simple varactor test jig
diodes (used as an example). My results of
testing and graphing the measurements of
this varicap diode. The test circuit seems to
work fine. My results of testing these diodes
seems to indicate they are the real McCoy.
I did a large buy of these components and
have started to sell some of them. CLICK ON
THE LINK BELOW FOR THIS TOPIC
simple varactor test jig
OLDER DIGITAL READOUT CHIPS FROM THE
MID TO LATE 1970S. As used on the FT301
Transceiver.
These old chips/readouts (both logic
circuitry and driver and readout all on one
chip). They are often hard to buy or very
expensive to buy. Just punch TIL 306 or TIL
308 into ebay and you will be shocked. I
have seen them as high as $360 each!!!
THIS TOPIC TO BE WRITTEN VERY SOON.
MID TO LATE 1970S. As used on the FT301
Transceiver.
These old chips/readouts (both logic
circuitry and driver and readout all on one
chip). They are often hard to buy or very
expensive to buy. Just punch TIL 306 or TIL
308 into ebay and you will be shocked. I
have seen them as high as $360 each!!!
THIS TOPIC TO BE WRITTEN VERY SOON.
Early May 2011..I am measuring some
inductances and cores. In particular the
small ferrite cores I have, use and I also
sell some from time to time.
I set about to measure and verify their
characteristics. Material Identification. I
used to do this sort of work in a previous
occupation. CLICK HERE FOR THIS PAGE
inductances and cores. In particular the
small ferrite cores I have, use and I also
sell some from time to time.
I set about to measure and verify their
characteristics. Material Identification. I
used to do this sort of work in a previous
occupation. CLICK HERE FOR THIS PAGE
I was looking through my OPTO-electronics section the other day and I realized
that there were parts with-out part numbers and also display parts with either
NO PART NUMBER AT ALL..or some part number that I could not find any data for.
NO data..NO PINOUTS..and the part is basically useless until I get a data sheet or
find some basic information ..ie ..which piece of equipment it is a spare part for!!
--- Below pictured..I have started to build a test jig to UNLOCK the information
about some of these mystery parts. It will also DOUBLE PURPOSE to test the
parts..to make sure they work. Below is a TIL 308 I tested. IT IS a simple part to
test. I have a data sheet and truth table and connection diagram. The TIL 308 has
a LAMP TEST feature. Very handy for testing. When one of the pins is grounded
all the individual displays light up! Its close cousin
the TIL 306 does not seem to have this function-- so it may be more difficult to
test. I will be wiring up a bunch of on off on switches in a switch bank and will be
wiring up some other simple switching circuitry to make up a complete test jig
for opto electronic displays. I will write up the completed project on my web
pages this fall.
that there were parts with-out part numbers and also display parts with either
NO PART NUMBER AT ALL..or some part number that I could not find any data for.
NO data..NO PINOUTS..and the part is basically useless until I get a data sheet or
find some basic information ..ie ..which piece of equipment it is a spare part for!!
--- Below pictured..I have started to build a test jig to UNLOCK the information
about some of these mystery parts. It will also DOUBLE PURPOSE to test the
parts..to make sure they work. Below is a TIL 308 I tested. IT IS a simple part to
test. I have a data sheet and truth table and connection diagram. The TIL 308 has
a LAMP TEST feature. Very handy for testing. When one of the pins is grounded
all the individual displays light up! Its close cousin
the TIL 306 does not seem to have this function-- so it may be more difficult to
test. I will be wiring up a bunch of on off on switches in a switch bank and will be
wiring up some other simple switching circuitry to make up a complete test jig
for opto electronic displays. I will write up the completed project on my web
pages this fall.
| Broken or Missing Ferrite Slugs..I have a collection of these parts and I sort them for my own use but I can sell them for a dollar or two..something like that. I don't charge hourly labour..because I keep these for my own projects and tinkering anyways. |
| Below: the oscillator core for a coil beside the main tuning capacitor in a TEN TEC PM2 qrp transceiver (very early 1970s vintage). A fellow wrote me because he needed this core which was missing. I used a junker PM2 and donated a core. Its inductance with the test winding was about .740 uh whereas the other cores I tried from other old coils were about .450 or so. It is a matter of matching up material with the test winding. I do this as a very low cost service to other hams, tinkerers, potential hams and perhaps students who are doing a school project or something. |
The inductance meter (in the picture left) I'm using is from an ebay purchase.
Seems to give definitive measurements..which seem to be repeatable. Not sure
how they would compare to a piece of professional (properly calibrated) piece of
lab equipment. But for comparative measurements..it is very good for my use.
Sometimes ferrite cores are broken because they get stuck and the person uses
excessive force to remove the core. Sometimes they use a metal hex wrench.
All no no's!! Ferrite fractures. It can be glued back together with crazy glue but
better to use a lubricant -- perhaps..some thinned down mineral oil ..thinned
with pure alcohol. Im just guessing!!! Google the situation and take extra care
and time and the core wont break.
Seems to give definitive measurements..which seem to be repeatable. Not sure
how they would compare to a piece of professional (properly calibrated) piece of
lab equipment. But for comparative measurements..it is very good for my use.
Sometimes ferrite cores are broken because they get stuck and the person uses
excessive force to remove the core. Sometimes they use a metal hex wrench.
All no no's!! Ferrite fractures. It can be glued back together with crazy glue but
better to use a lubricant -- perhaps..some thinned down mineral oil ..thinned
with pure alcohol. Im just guessing!!! Google the situation and take extra care
and time and the core wont break.
MANY..of the electronic components are "STANDARD". There are organizations which work towards standardization
of things such as labelling of consumer goods, bar codes, computer formats, LOGIC Families such as TTL, ECL,
CMOS, ect and nuts and bolts.
This is in order that you can easily find on the store shelf or order with confidence things such as threaded bolts and
screws and transistors. NATO has the Stanags or Nato Standardization Agreements. The electronics industry has
organizations such as JEDEC (Joint Electron Device Engineering Council. Electronic Components are pretty well
standardized so that a 2N2222A manufactured by National Semiconductor is fit, form, function, and specification ..pin
for pin..drop in replacement for a 2N2222A manufactured by Motorola or some other company.
When I was working for Government in Canada, (way back when!!); I had a pretty good handle on the electronic
components standardization practices (and problems). Often..there are some fine lines of distinction between very
similar items that are (supposed) to be the same. There are often variances in performance or testing ect and the
Nato Cataloguing System was (often) trying to keep everything well organized and compatible for all users. NOT EASY
when there are many users.
Anyways..I now operate my own shop. I group like items together and I have my own way of organizing my stock.
I dont use NATO Stock numbers. I often use NTE numbers which group similar items together in a useful way.
So if you are looking for a dual gate mosfet..I will often look a cross reference NTE number and trace it to my stocks,
or visa versa.
of things such as labelling of consumer goods, bar codes, computer formats, LOGIC Families such as TTL, ECL,
CMOS, ect and nuts and bolts.
This is in order that you can easily find on the store shelf or order with confidence things such as threaded bolts and
screws and transistors. NATO has the Stanags or Nato Standardization Agreements. The electronics industry has
organizations such as JEDEC (Joint Electron Device Engineering Council. Electronic Components are pretty well
standardized so that a 2N2222A manufactured by National Semiconductor is fit, form, function, and specification ..pin
for pin..drop in replacement for a 2N2222A manufactured by Motorola or some other company.
When I was working for Government in Canada, (way back when!!); I had a pretty good handle on the electronic
components standardization practices (and problems). Often..there are some fine lines of distinction between very
similar items that are (supposed) to be the same. There are often variances in performance or testing ect and the
Nato Cataloguing System was (often) trying to keep everything well organized and compatible for all users. NOT EASY
when there are many users.
Anyways..I now operate my own shop. I group like items together and I have my own way of organizing my stock.
I dont use NATO Stock numbers. I often use NTE numbers which group similar items together in a useful way.
So if you are looking for a dual gate mosfet..I will often look a cross reference NTE number and trace it to my stocks,
or visa versa.
| link back to my home page (de..earl ve3ab) up here in Elliot Lake Ontario..(northern Ontario). www.hamelectronicsmagazine.com CLICK HERE TO VISIT HOME PAGE es 73 |
| Transistor Characteristic Matching. quick HFE matching using my V.O.M. (SMALL TRANSISTORS I dont charge for that service -- for larger RF transistors like the MRF476s in the pic below..I charge a nominal $1 to match up a pair. |
I got this circuit from a site called the QRP builder..qrp pops. I remember in College back
in the mid to late 70s when I was taking my 2 yr electronic Technician Course at Algonquin
College..the text books had circuits and discussions along these lines to measuring and
calculating DC Beta of Transistors.
in the mid to late 70s when I was taking my 2 yr electronic Technician Course at Algonquin
College..the text books had circuits and discussions along these lines to measuring and
calculating DC Beta of Transistors.
It is a good idea ..when building test jigs or circuits..to keep the schematic on hand in a file..or as I did in this case..I affixed it to the bottom of the circuit board. I also noted that I use
12.5 volts as the supply voltage. This is a constant and means the tags I put on the transistors are relative to this. The 5.65 and 5.56 VDC measured from collector to ground in my
test jig for two of the transistors..means they are fairly close in characteristic and I would sell them as a matched pair.
These MRF476/2sc2075s are fairly high gain transistors. I think they have up to 17db gain. They are used in the Argonaut 515 and also the Ten Tec Argo 556 (like the Scout).
12.5 volts as the supply voltage. This is a constant and means the tags I put on the transistors are relative to this. The 5.65 and 5.56 VDC measured from collector to ground in my
test jig for two of the transistors..means they are fairly close in characteristic and I would sell them as a matched pair.
These MRF476/2sc2075s are fairly high gain transistors. I think they have up to 17db gain. They are used in the Argonaut 515 and also the Ten Tec Argo 556 (like the Scout).
I asked some vendors on the web..if they would match transistors for me..and they said NO. The larger vendors..generally don't have time to get this involved. RF Parts in
California does do matching and I have bought matched pair of transistors MRF450s for my little ten tec 50 watt amplifier.
Since I am so small a vendor..I have to think of ways to SERVICE clients to make my services stand out. -- I certainly don't have the selection of parts and quantities BUT..I can offer
extra services such as transistor matching at a very low $1 per pair of transistors and free hfe test/match for small transistors.
California does do matching and I have bought matched pair of transistors MRF450s for my little ten tec 50 watt amplifier.
Since I am so small a vendor..I have to think of ways to SERVICE clients to make my services stand out. -- I certainly don't have the selection of parts and quantities BUT..I can offer
extra services such as transistor matching at a very low $1 per pair of transistors and free hfe test/match for small transistors.
IF YOU NEED A CERTAIN VALUE RANGE OF
VARIABLE CAPACITANCE..I COULD MEASURE
UP SOME OF THE MANY VARICAPS I have
around here. I had about a 100 or so ..loose
non confirmed value/part number ones that
were just given to me some time ago.
VARIABLE CAPACITANCE..I COULD MEASURE
UP SOME OF THE MANY VARICAPS I have
around here. I had about a 100 or so ..loose
non confirmed value/part number ones that
were just given to me some time ago.
Last year..I bought about 600 MV1662 types off a vendor on ebay. Wasnt
absolutely sure about the transaction and the varactors but I built up this test jig
and measured some of them at random and they matched the MV1662 curves
very very closely..so..I am sure they are the real McCoy.
absolutely sure about the transaction and the varactors but I built up this test jig
and measured some of them at random and they matched the MV1662 curves
very very closely..so..I am sure they are the real McCoy.
| 15th Feb 2012..SOME specifics concerning testing of OPTO Electronics; vintage and old parts. |
I am working this week on a project that someone sent me in the mail from USA. There were 3 circuit boards and it cost the person about $5.60 to
send me the boards. To send the (extracted parts) back it will cost roughly the same amount. There will be (about) 25 exracted parts, most of which
will be the old Texas Instrument TIL 308 seven segment displays. -- These parts are almost impossible to buy at a reasonable price. I just went on
ebay and found some listed as "BUY IT NOW' price of $502.73 or best offer. I did a check on the similar TIL 306 part and found it listed in a smilar
way for $342.12.
For fun..I then typed the actual part number "TIL 308" into an internet search engine..and to my surprise..there was a site called "TIL308.com"!!
So..there is still a demand for these older parts from the mid seventies to early 80s vintage. TIL308.com has a new substitute chip for sale with part
number VIN308RP. This substitute part has a price tag of $225.50. Still a hefty price tag for sure.
I DO EXTRACTION OF PARTS SUCH AS THE TIL308, TIL 306, and other valuable old chips for my low bench rate of $10 per hour. I test the part in my
home made test jig. General ball park price per IC of extraction and testing of each part is about $5.00 each. For certain old vintage parts and/or
rare ICs..this is a good deal and makes sense to do it by MAIL ORDER.
The TIL 308/306 and series of parts like this are TTL and as such are not particularly sensitive to static damage. Certainly not like the CMOS or
NMOS or dual gate mosfets. I happened to buy a TIL 308 at a yard sale that was in a plastic bin. There was a date/lot code of 1976 and no attention
was given by the previous owner..to proper storage in a static bag. It was just kicking around loose in a plastic drawer. It worked fine when tested.
There was only one in the drawers of parts...unfortunately.
The discontinued parts of today could be worth big bucks tommorrow. There is a specific group of companies offering OBSOLETE AND HARD TO
FIND COMPONENTS to business and government buyers. When I worked in the Federal Government prior to 2004, I would get lists from companies
of items they were discontinuing and we would try and order enough spare parts to last us for the life of the equipment. This was an effort to
minimize the need to go to companies such as Rochester Electronics (obsolete parts for military/industry). A company that does this today..that I
just happened to google right now is MID WEST COMPONENTS. Here is their sales pitch: "We specialize in finding electronic components, whether
obsolete ICs or otherwise hard to find electronic parts. We can also locate datasheets or alternate sources, provide value-added services like
bonded inventory or deliver components to you repackaged or temperature screened and tested to your requirements"
send me the boards. To send the (extracted parts) back it will cost roughly the same amount. There will be (about) 25 exracted parts, most of which
will be the old Texas Instrument TIL 308 seven segment displays. -- These parts are almost impossible to buy at a reasonable price. I just went on
ebay and found some listed as "BUY IT NOW' price of $502.73 or best offer. I did a check on the similar TIL 306 part and found it listed in a smilar
way for $342.12.
For fun..I then typed the actual part number "TIL 308" into an internet search engine..and to my surprise..there was a site called "TIL308.com"!!
So..there is still a demand for these older parts from the mid seventies to early 80s vintage. TIL308.com has a new substitute chip for sale with part
number VIN308RP. This substitute part has a price tag of $225.50. Still a hefty price tag for sure.
I DO EXTRACTION OF PARTS SUCH AS THE TIL308, TIL 306, and other valuable old chips for my low bench rate of $10 per hour. I test the part in my
home made test jig. General ball park price per IC of extraction and testing of each part is about $5.00 each. For certain old vintage parts and/or
rare ICs..this is a good deal and makes sense to do it by MAIL ORDER.
The TIL 308/306 and series of parts like this are TTL and as such are not particularly sensitive to static damage. Certainly not like the CMOS or
NMOS or dual gate mosfets. I happened to buy a TIL 308 at a yard sale that was in a plastic bin. There was a date/lot code of 1976 and no attention
was given by the previous owner..to proper storage in a static bag. It was just kicking around loose in a plastic drawer. It worked fine when tested.
There was only one in the drawers of parts...unfortunately.
The discontinued parts of today could be worth big bucks tommorrow. There is a specific group of companies offering OBSOLETE AND HARD TO
FIND COMPONENTS to business and government buyers. When I worked in the Federal Government prior to 2004, I would get lists from companies
of items they were discontinuing and we would try and order enough spare parts to last us for the life of the equipment. This was an effort to
minimize the need to go to companies such as Rochester Electronics (obsolete parts for military/industry). A company that does this today..that I
just happened to google right now is MID WEST COMPONENTS. Here is their sales pitch: "We specialize in finding electronic components, whether
obsolete ICs or otherwise hard to find electronic parts. We can also locate datasheets or alternate sources, provide value-added services like
bonded inventory or deliver components to you repackaged or temperature screened and tested to your requirements"
Here are some pictures of my current job that I'm doing by MAIL ORDER. I build test jigs and test the parts as well as extract them from their original circuit boards. I
use a simple desoldering hand tool and I use solder flux. I have air filters (HEPA) filters on when doing this work. There are fumes that need to be extracted and I try
not to breathe in too much of the solder smoke. Back when these displays were being used (later 1970s through the 80s mainly), the solder contained a good high
percentage of LEAD.
IF ..I were doing a good number of these boards..I would wait till a nice sunny day outside ..not too hot..and do the work in the outdoors with a small fan to blow the
fumes away from me.
IF YOU HAVE THIS TYPE OF WORK YOU WANT DONE..I can do it for a very reasonable price by MAIL or courier. MY EMAIL ADDRESS is LINK HERE.
use a simple desoldering hand tool and I use solder flux. I have air filters (HEPA) filters on when doing this work. There are fumes that need to be extracted and I try
not to breathe in too much of the solder smoke. Back when these displays were being used (later 1970s through the 80s mainly), the solder contained a good high
percentage of LEAD.
IF ..I were doing a good number of these boards..I would wait till a nice sunny day outside ..not too hot..and do the work in the outdoors with a small fan to blow the
fumes away from me.
IF YOU HAVE THIS TYPE OF WORK YOU WANT DONE..I can do it for a very reasonable price by MAIL or courier. MY EMAIL ADDRESS is LINK HERE.
5 inputs control the TIL 308 display. These displays were probably just registering garbage. A data line would probably BLANK THE DISPLAY if it were connected to
equipment. 4 inputs control the 0 through 9 numeric display. Mostly TTL inputs float HIGH when left floating. A binary 1111 or HHHH displays an F as in this case. The
decimal point is also a floating INPUT and floats High and therefore a decimal point is displayed.
equipment. 4 inputs control the 0 through 9 numeric display. Mostly TTL inputs float HIGH when left floating. A binary 1111 or HHHH displays an F as in this case. The
decimal point is also a floating INPUT and floats High and therefore a decimal point is displayed.
| I do other jobs by MAIL ORDER. Feel free to send me an email and I can give you my phone number if you wish to talk. My $10 per hour (at home) shop is a small retirement activity AND I'm s l o w l y ..getting more and more little jobs to do. I will see ..maybe it can turn into a small way to supplement my retirement income..especially if the investments dont come back as fast as I would like. |
| These pages are being worked on from time to time..thanks Earl Andrews Elliot Lake Ontario. PS..I also have a DOMAIN NAME FOR SALE..www.sparetime.biz |