Re: [time-nuts] GC-1000 Clock Cap Choice?
Also they are almost impossible to solder by hand without setting high internal stress which sometimes results in cracks, not necessarily immediately. Even on professional wave solder equipment, high delayed failure rates are not uncommon, which sometimes results in many units having to be recalled. Don't ask me how I know, I was lucky this was not my design, but it could have been. Yet, I still use them, under the assurance that our manufacturing folks have resolved the problem, which for now seems true. Didier Sent from my Verizon Wireless BlackBerry -Original Message- From: Chuck Harris cfhar...@erols.com Sender: time-nuts-boun...@febo.com Date: Sun, 16 Jan 2011 17:43:18 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] GC-1000 Clock Cap Choice? I have found that such high dielectric constant capacitors have other problems in some circuits. While the capacitance value is dropping, as much as 50% when you apply voltage, their physical volume is changing. They behave as piezoelectric transducers. I have used them inappropriately, and found them singing loudly. If that were to happen in a switching regulator, I would think the ultrasonic vibrations could do damage to the capacitor, the PCB, or the solder joints. -Chuck Harris Poul-Henning Kamp wrote: In message4d336a19.40...@freenet.de, Dr. Frank Stellmach writes: High cap value Ceramics are available since years, [...] Can you clarify one thing for me: When I studied datasheets for these it looked like they drop 50% of their capacitance at a DC voltage of 10-20V. Doesn't that make them a so-so bargain for power supply bulk capacitance ? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GC-1000 Clock Cap Choice?
Hi Didier: I know CMAX had a real problem with their LF time receiver boards. The high value caps used to resonate the loop-stick antenna permanently changed value so much when heated to soldering temperature they no longer worked. Now they use radial lead caps shrink wrapped to the loop-sticks instead of having the cap on the receiver PCB. Have Fun, Brooke Clarke http://www.PRC68.com shali...@gmail.com wrote: Also they are almost impossible to solder by hand without setting high internal stress which sometimes results in cracks, not necessarily immediately. Even on professional wave solder equipment, high delayed failure rates are not uncommon, which sometimes results in many units having to be recalled. Don't ask me how I know, I was lucky this was not my design, but it could have been. Yet, I still use them, under the assurance that our manufacturing folks have resolved the problem, which for now seems true. Didier Sent from my Verizon Wireless BlackBerry -Original Message- From: Chuck Harriscfhar...@erols.com Sender: time-nuts-boun...@febo.com Date: Sun, 16 Jan 2011 17:43:18 To: Discussion of precise time and frequency measurementtime-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] GC-1000 Clock Cap Choice? I have found that such high dielectric constant capacitors have other problems in some circuits. While the capacitance value is dropping, as much as 50% when you apply voltage, their physical volume is changing. They behave as piezoelectric transducers. I have used them inappropriately, and found them singing loudly. If that were to happen in a switching regulator, I would think the ultrasonic vibrations could do damage to the capacitor, the PCB, or the solder joints. -Chuck Harris Poul-Henning Kamp wrote: In message4d336a19.40...@freenet.de, Dr. Frank Stellmach writes: High cap value Ceramics are available since years, [...] Can you clarify one thing for me: When I studied datasheets for these it looked like they drop 50% of their capacitance at a DC voltage of 10-20V. Doesn't that make them a so-so bargain for power supply bulk capacitance ? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GC-1000 Clock Cap Choice?
Good tidbit on the cmax On Thu, Jan 20, 2011 at 10:29 AM, Brooke Clarke bro...@pacific.net wrote: Hi Didier: I know CMAX had a real problem with their LF time receiver boards. The high value caps used to resonate the loop-stick antenna permanently changed value so much when heated to soldering temperature they no longer worked. Now they use radial lead caps shrink wrapped to the loop-sticks instead of having the cap on the receiver PCB. Have Fun, Brooke Clarke http://www.PRC68.com shali...@gmail.com wrote: Also they are almost impossible to solder by hand without setting high internal stress which sometimes results in cracks, not necessarily immediately. Even on professional wave solder equipment, high delayed failure rates are not uncommon, which sometimes results in many units having to be recalled. Don't ask me how I know, I was lucky this was not my design, but it could have been. Yet, I still use them, under the assurance that our manufacturing folks have resolved the problem, which for now seems true. Didier Sent from my Verizon Wireless BlackBerry -Original Message- From: Chuck Harriscfhar...@erols.com Sender: time-nuts-boun...@febo.com Date: Sun, 16 Jan 2011 17:43:18 To: Discussion of precise time and frequency measurement time-nuts@febo.com Reply-To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] GC-1000 Clock Cap Choice? I have found that such high dielectric constant capacitors have other problems in some circuits. While the capacitance value is dropping, as much as 50% when you apply voltage, their physical volume is changing. They behave as piezoelectric transducers. I have used them inappropriately, and found them singing loudly. If that were to happen in a switching regulator, I would think the ultrasonic vibrations could do damage to the capacitor, the PCB, or the solder joints. -Chuck Harris Poul-Henning Kamp wrote: In message4d336a19.40...@freenet.de, Dr. Frank Stellmach writes: High cap value Ceramics are available since years, [...] Can you clarify one thing for me: When I studied datasheets for these it looked like they drop 50% of their capacitance at a DC voltage of 10-20V. Doesn't that make them a so-so bargain for power supply bulk capacitance ? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GC-1000 Clock Cap Choice?
On 01/16/2011 11:15 PM, Poul-Henning Kamp wrote: In message4d336a19.40...@freenet.de, Dr. Frank Stellmach writes: High cap value Ceramics are available since years, [...] Can you clarify one thing for me: When I studied datasheets for these it looked like they drop 50% of their capacitance at a DC voltage of 10-20V. Doesn't that make them a so-so bargain for power supply bulk capacitance ? High dielectric constant comes at a high price performance wise. :) You gain some, you loose some. Temperature performance and linearity. It should not come as a surprise if you start to think about what happens on the atomic/molecular level of dielectrics, it's a combination of electrostatics and mechanical stress. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GC-1000 Clock Cap Choice?
Hi Magnus: I've just placed an order for 16 different kinds of caps. Most of them are either low leakage or low series resistance electrolytic types but also a small number of plastic film caps. Should be here in a few days. Also have replacements for the tone decoder PLL ICs and the Op Amps that drive them, but will replace the caps first and see what happens. Have Fun, Brooke Clarke http://www.PRC68.com Magnus Danielson wrote: On 01/16/2011 11:15 PM, Poul-Henning Kamp wrote: In message4d336a19.40...@freenet.de, Dr. Frank Stellmach writes: High cap value Ceramics are available since years, [...] Can you clarify one thing for me: When I studied datasheets for these it looked like they drop 50% of their capacitance at a DC voltage of 10-20V. Doesn't that make them a so-so bargain for power supply bulk capacitance ? High dielectric constant comes at a high price performance wise. :) You gain some, you loose some. Temperature performance and linearity. It should not come as a surprise if you start to think about what happens on the atomic/molecular level of dielectrics, it's a combination of electrostatics and mechanical stress. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GC-1000 Clock Cap Choice?
Brooke, On 01/19/2011 09:31 PM, Brooke Clarke wrote: Hi Magnus: I've just placed an order for 16 different kinds of caps. Most of them are either low leakage or low series resistance electrolytic types but also a small number of plastic film caps. Should be here in a few days. It would be interesting to try these out with a capacitance meter at various temperatures. See how capacitance and loss changes over time. The memory effect would also be fun to test if it changes. Should be enlightening. Another thing would be to see how it varies with applied voltage. Also have replacements for the tone decoder PLL ICs and the Op Amps that drive them, but will replace the caps first and see what happens. Sounds like a fun project. Have fun! Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] GC-1000 Clock Cap Choice?
Hi: More than half the electrolytic caps in this Heathkit GC-1000 Most Accurate Clock are bad and I'm trying to come up with modern replacements. http://www.prc68.com/I/HeathkitGC1000.shtml#Rx The Tone Decoder board uses a couple of NE567 PLL ICs to capture the 100 Hz and 1000 Hz WWV tones. Heathkit used Tantalum caps for the PLL output filter. I'd think something like a low loss electrolytic or plastic cap would be better. http://www.prc68.com/I/HeathkitGC1000.shtml#TB Also how about using Aluminum Organic Polymer caps (where there are replacements) instead of the plain electrolytic caps? The plan is to replace all the electrolytic and tantalum caps since the ones that are now OK may fail in the near future. Any thoughts? -- Have Fun, Brooke Clarke http://www.PRC68.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GC-1000 Clock Cap Choice?
Also how about using Aluminum Organic Polymer caps (where there are replacements) instead of the plain electrolytic caps? One problem with using low ESR caps is that some regulators depend upon the ESR for stability. The plan is to replace all the electrolytic and tantalum caps since the ones that are now OK may fail in the near future. Why replace the tantalums? Do they dry out like electrolytics? I poked around a bit and found a couple of web pages that said no-problems, but both specifically referred to solid tantalums. Are there versions using a liquid? -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] GC-1000 Clock Cap Choice?
Hi Brooke, Our electronics designers (@automotive electronics supplier) have to take lot of care concerning voltage stabilizers, that the cap provides sufficiently low ESR, which electrolytics deliver only at much higher capacitance value; and a series resistor is introduced to limit loading currents of the Tantalum. Otherwise, the Tantalums might fail, either open, or they might burn, which already caused total damage of vehicles (Mercedes). I assume, latter aspect has been overseen in your device. This is the main fault modus of Tantalums. Electrolytics dry out over the years, especially when stored non-operating, Tantalums do not at all. You have to chose higher cap value and higher environmental temperature grade (= 105°C) for the ElCo, to get a reliable replacement. I commonly do not recommend polymer elcos, they have some further disadvantages, one being the price, the other (perhaps) being CN compounds in the polymer, which may be poisonous in case of fire. High cap value Ceramics are available since years, therefore , if price is no argument, I'd prefer to take them for values up to ~ 100µF; X5R ceramics should be good enough. With some luck, they (SMD type) fit to the existing pads on the solder side. Otherwise, you have to analyse the (misdesigned) circuitry for possible high pulse currents, and replace the bad tantalums by new ones in series with a limiting resistor. Several tantalums in parallel might also improve withstanding to current pulses. Check the tantalums datasheets. epcos has got some detailed application hints, as far as I remember. regards Frank ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GC-1000 Clock Cap Choice?
In message 4d336a19.40...@freenet.de, Dr. Frank Stellmach writes: High cap value Ceramics are available since years, [...] Can you clarify one thing for me: When I studied datasheets for these it looked like they drop 50% of their capacitance at a DC voltage of 10-20V. Doesn't that make them a so-so bargain for power supply bulk capacitance ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GC-1000 Clock Cap Choice?
I have found that such high dielectric constant capacitors have other problems in some circuits. While the capacitance value is dropping, as much as 50% when you apply voltage, their physical volume is changing. They behave as piezoelectric transducers. I have used them inappropriately, and found them singing loudly. If that were to happen in a switching regulator, I would think the ultrasonic vibrations could do damage to the capacitor, the PCB, or the solder joints. -Chuck Harris Poul-Henning Kamp wrote: In message4d336a19.40...@freenet.de, Dr. Frank Stellmach writes: High cap value Ceramics are available since years, [...] Can you clarify one thing for me: When I studied datasheets for these it looked like they drop 50% of their capacitance at a DC voltage of 10-20V. Doesn't that make them a so-so bargain for power supply bulk capacitance ? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] GC-1000 Clock Cap Choice?
Can you clarify one thing for me: When I studied datasheets for these it looked like they drop 50% of their capacitance at a DC voltage of 10-20V. Doesn't that make them a so-so bargain for power supply bulk capacitance ? Poul-Henning, Pls. check the spec for dielectric material. X5R is automotive grade, interior applications (up to 85°C) ; X7R would be engine applications (= 125°C). Those ceramics don't have such high detoriation of cap vs. T and V. For example, Y5V is commercial application range and might have such problems. Frank ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GC-1000 Clock Cap Choice?
Hi The other thing to watch out for is the temperature coefficient. Some of the high K materials move a *lot* with modest changes in temperature. There are indeed industry standards on what a given dielectric code should be. In some cases there have ben liberties taken interpreting the codes. You really need to go back to the original data sheet on each part to see what the temp co actually is. In a modestly warm box (say 60 C) the net effect between voltage and temperature may be that you have 1/4 your original capacitance. Bob On Jan 16, 2011, at 5:15 PM, Poul-Henning Kamp wrote: In message 4d336a19.40...@freenet.de, Dr. Frank Stellmach writes: High cap value Ceramics are available since years, [...] Can you clarify one thing for me: When I studied datasheets for these it looked like they drop 50% of their capacitance at a DC voltage of 10-20V. Doesn't that make them a so-so bargain for power supply bulk capacitance ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GC-1000 Clock Cap Choice?
In message a9103007-9686-4310-a9e5-aa8b193d1...@rtty.us, Bob Camp writes: In a modestly warm box (say 60 C) the net effect between voltage and temperature may be that you have 1/4 your original capacitance. That was sort of my conclusion too, not exactly the first thing that springs to mind when you read the datasheet either, is it ? Thanks for confirming my suspicion. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] GC-1000 Clock Cap Choice?
I have found that such high dielectric constant capacitors have other problems in some circuits. While the capacitance value is dropping, as much as 50% when you apply voltage, their physical volume is changing. They behave as piezoelectric transducers. I have used them inappropriately, and found them singing loudly. If that were to happen in a switching regulator, I would think the ultrasonic vibrations could do damage to the capacitor, the PCB, or the solder joints. -Chuck Harris We use ceramics widely in our applications, also switching power supplies and PWM circuits. Our customers always search intensivley for audible and visual problems before accepting our products, (we design instrument clusters). (X5R) ceranic capacitors did not yet pose any audible problems, but singing inductors did. It is also known, that ceramics'* piezo effect is problematic for audio amplifiers. I have to admit, that we do not use very high value caps; several µF is oK, higher values are either too expensive compared to ElCo and Ta, or too bulky. Anyhow, if our dear customers require us to avoid Tantalums for safety concerns, Ceramics are looked upon first. Frank ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] GC-1000 Clock Cap Choice
If you've ever worked on more than a very few Tektronix TM-500 series modules, you are well aware of the favorite epoxy dipped tantalum capacitor failure mode... very low resistance dead short... usually ending up in a charred stinky black blob. Whatever manufacturer they chose... was the wrong one. There are wet-slug tantalum caps out there. Usually hermetically sealed military grade units. For the clock, I'd use whatever cap came to hand. I would not go out of my way to find some swoopty-do new fangled replacement. It's a Heathkit, not a space qualified doomaflotchy. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] GC-1000 Clock Cap Choice
Sorry, epcos sold ceramics business, and was itself swallowed by TDK. If looking for X5R and X7R cer caps, visit vishay, kemet, taiyo yuden, murata and others instead. This special material specification is well hidden at the official manufacturers specs. Those are high grade ceramic dielectrics, realtively cheap, not necessarily space qualified, only automotive, and especially not an exotic component anymore. If Tek had problems with tantalums in the past, they either have chosen bad suppliers (reliable / safe production is critical), or that was at the time, where the failure mechanisms were not understood well, or they have ignored application hints. Today, its possible to use Tantalums safely even in automotive applications, that goes for ceramics also. Its - as always - a question of component knowledge and reliability engineering. Frank ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GC-1000 Clock Cap Choice?
Brooke,
WTF ! Just replace them with the same type as was in there. That will give you
another 20 or so years and by then you will be dead and won't give a damn.
The only critical (for that time) component would be the TC loop capacitors
for
the 567 PLL's. They should be silver mica types (good enough tempco for the
567's), but knowing heathkit they might have just used common disk ceramic types
(bad for tempco).
All these other people going crazy with all the {RE} engineering crack me up.
No
thought as to what is really needed to fix the item. All they truly do is
create
a given level of noise that exceeds the original expectations of this list.
Well, one other thought . . . . . but I would hate to accuse you of trolling,
73BillWB6BNQ
Brooke Clarke wrote:
Hi:
More than half the electrolytic caps in this Heathkit GC-1000 Most
Accurate Clock are bad and I'm trying to come up with modern replacements.
http://www.prc68.com/I/HeathkitGC1000.shtml#Rx
The Tone Decoder board uses a couple of NE567 PLL ICs to capture the 100
Hz and 1000 Hz WWV tones. Heathkit used Tantalum caps for the PLL
output filter. I'd think something like a low loss electrolytic or
plastic cap would be better.
http://www.prc68.com/I/HeathkitGC1000.shtml#TB
Also how about using Aluminum Organic Polymer caps (where there are
replacements) instead of the plain electrolytic caps?
The plan is to replace all the electrolytic and tantalum caps since the
ones that are now OK may fail in the near future.
Any thoughts?
--
Have Fun,
Brooke Clarke
http://www.PRC68.com
___
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Re: [time-nuts] GC-1000 Clock Cap Choice?
Thanks, I needed that (wiping off the cold water [I hope] from the
deluge delivered).
Indeed, there is nothing special about 60 Hz (even though Hertz
never resonated anything at 60 cycles per second) filter capacitors.
There is nothing special about 100 and 1000 cps PLLs either. A good
plastic cap should be fine. I'd be more worried about the resistors,
unless the PLL caps were electrolytics. The output filters should be
low pass, which are not particularly critical.
Disclaimer: I don't have a GC-1000 manual or schematic. Most of this
is based on the outcome of shotgunning the caps in an R-390 class
receiver. Brooke's tables of marked versus measured capacities sure
do indicate the need for replacement, but not with anything exotic.
Bill Hawkins
P.S. You don't know that he'll be dead in 20 years, but there is a
high probability that he'll be beyond caring. I mean, if an interviewer
asked you what was the most important thing that happened to you during
your life, the one that you would like to live over before you die,
would you name the day you got your GC-1000 working?
Was this a troll? You decide . . .
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of WB6BNQ
Sent: Sunday, January 16, 2011 7:41 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] GC-1000 Clock Cap Choice?
Brooke,
WTF ! Just replace them with the same type as was in there. That will give
you
another 20 or so years and by then you will be dead and won't give a damn.
The only critical (for that time) component would be the TC loop
capacitors for
the 567 PLL's. They should be silver mica types (good enough tempco for the
567's), but knowing heathkit they might have just used common disk ceramic
types
(bad for tempco).
All these other people going crazy with all the {RE} engineering crack me
up. No
thought as to what is really needed to fix the item. All they truly do is
create
a given level of noise that exceeds the original expectations of this list.
Well, one other thought . . . . . but I would hate to accuse you of
trolling,
73BillWB6BNQ
Brooke Clarke wrote:
Hi:
More than half the electrolytic caps in this Heathkit GC-1000 Most
Accurate Clock are bad and I'm trying to come up with modern replacements.
http://www.prc68.com/I/HeathkitGC1000.shtml#Rx
The Tone Decoder board uses a couple of NE567 PLL ICs to capture the 100
Hz and 1000 Hz WWV tones. Heathkit used Tantalum caps for the PLL
output filter. I'd think something like a low loss electrolytic or
plastic cap would be better.
http://www.prc68.com/I/HeathkitGC1000.shtml#TB
Also how about using Aluminum Organic Polymer caps (where there are
replacements) instead of the plain electrolytic caps?
The plan is to replace all the electrolytic and tantalum caps since the
ones that are now OK may fail in the near future.
Any thoughts?
--
Have Fun,
Brooke Clarke
http://www.PRC68.com
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