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 Post subject: CCI's beautiful frequency counter.
PostPosted: Mar Fri 26, 2021 11:31 pm 
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Communications Concepts Inc (CCI), once made a really nice frequency counter, the TK-1. It was designed as an add on typically for tube radios or others, where a digital frequency display would help. Since this was made a plethora of modern counters with PIC uP's have appeared.

The CCI design was very clever though, especially in one respect and it beats all my other counters, it has no last digit (100Hz) flicker. Somebody at CCI noticed that in most counter designs they start with a divide by 10, but it is preferable initially to start with an initial divide by 2, so they used, after their input transistor pre-amplifier a divide by 8 using a 74LS93.

Their crystal timebase is 2.4576MHz and the display is updated at a rate of 9.375Hz. The used DIP switches to offset the IF frequency as required to suit the radio's IF. The counter, as they made it worked over a range of 100kHz to 50MHz. So it was a perfect add on for a tube shortwave radio or comms radio. Generally the input sensitivity was around 25mV.

There was another counter kit, using LED's in the same era called a DFD4 (which later became an LCD version or the DFD4 title used)

The effect with the CCI counter design is excellent, with really smooth changing of the display with analog tuning. I liked it so much that I added more display digits with a 1's and 10's of MHz column, went to TIL311 displays and put an additional RF preamp module (seen near the bnc socket) at the input, to get the sensitivity to a few mV and built their boards into my own enclosure. This enclosure has rechargeable batteries in its base and run or charges from a 12V source, it uses the LM309k regulator.

I got the TK-1 out the other day, to use with my ZC1 radio. I piped a trace of the radio's L/O to a connector on the front panel which was there to run a lamp. But because of this counter's sensitivity it reads it well. The radio tuned into a carrier on 2MHz. It reminded me of just how good these TK-1 counters were, I wish I had bought more of them when they were available.

It anyone else using a CCI TK-1 ?


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 Post subject: Re: CCI's beautiful frequency counter.
PostPosted: Mar Sat 27, 2021 12:30 am 
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Interesting
508 Millstone Dr. in Beavercreek Ohio is a residence.
Probably a one horse operation by an EE who is a ham. :D

-Steve


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Last edited by azenithnut on Mar Sat 27, 2021 10:36 am, edited 1 time in total.
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 Post subject: Re: CCI's beautiful frequency counter.
PostPosted: Mar Sat 27, 2021 1:47 am 
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Location: Oak Creek, WI USA
Is it still possible to build one to these specifications, or are there unobtainium parts in it?


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 Post subject: Re: CCI's beautiful frequency counter.
PostPosted: Mar Sat 27, 2021 2:43 am 
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Location: AUSTRALIA
Location: Queensland.
azenithnut wrote:
Interesting
508 Millstone Dr. in Beavercreek Ohio is a residence.
Probably a one horse operation by an EE who is/was a ham. :D

-Steve


Interesting.

They still supply wonderful RF transformers, amplifiers filters etc, I particularly like and use the type 77 pcb mount ferrite cores, have a look at the wonderful things:

http://www.communication-concepts.com/amplifiers/


Last edited by ACORNVALVE on Mar Sat 27, 2021 2:50 am, edited 1 time in total.

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 Post subject: Re: CCI's beautiful frequency counter.
PostPosted: Mar Sat 27, 2021 2:44 am 
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Paul Dietenberger wrote:
Is it still possible to build one to these specifications, or are there unobtainium parts in it?


It uses standard IC's and parts. There would just be the specific crystal. I wonder if they still have the pcb foil patterns.


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 Post subject: Re: CCI's beautiful frequency counter.
PostPosted: Mar Sat 27, 2021 6:14 am 
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Location: Corinth, TX, USA
You could always wirewrap it. I have seen WWed chasses running in excess of 40 MHz so I know it can be done.

John


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 Post subject: Re: CCI's beautiful frequency counter.
PostPosted: Mar Sat 27, 2021 10:37 am 
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Location: Dayton Ohio
ACORNVALVE wrote:
azenithnut wrote:
Interesting
508 Millstone Dr. in Beavercreek Ohio is a residence.
Probably a one horse operation by an EE who is/was a ham. :D

-Steve


Interesting.

They still supply wonderful RF transformers, amplifiers filters etc, I particularly like and use the type 77 pcb mount ferrite cores, have a look at the wonderful things:

http://www.communication-concepts.com/amplifiers/


Fasinating! I see some interesting products I might want to buy :D
Thank you for the link!

-Steve

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 Post subject: Re: CCI's beautiful frequency counter.
PostPosted: Mar Sat 27, 2021 11:14 pm 
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Paul Dietenberger wrote:
Is it still possible to build one to these specifications, or are there unobtainium parts in it?


keeps your eyes on ebay.. you might catch a lower cost FQ counter on there seen many. good luck

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 Post subject: Re: CCI's beautiful frequency counter.
PostPosted: Mar Sun 28, 2021 9:49 am 
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Location: Corinth, TX, USA
ACORNVALVE wrote:
The CCI design was very clever though, especially in one respect and it beats all my other counters, it has no last digit (100Hz) flicker. Somebody at CCI noticed that in most counter designs they start with a divide by 10, but it is preferable initially to start with an initial divide by 2, so they used, after their input transistor pre-amplifier a divide by 8 using a 74LS93.

What kind of radio in the CCI2 photo?

John


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 Post subject: Re: CCI's beautiful frequency counter.
PostPosted: Mar Sun 28, 2021 7:57 pm 
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Location: Phoenix AZ
ACORNVALVE wrote:
Communications Concepts Inc (CCI), once made a really nice frequency counter, the TK-1. It was designed as an add on typically for tube radios or others, where a digital frequency display would help.

Yes, ~45 years ago that frequency counter was beautiful. In fact around that time, I used a similar design which I wire wrapped and actually squeezed it into my Heathkit HW101 and replaced the entire mechanical dial.

Today if I wanted a digital frequency display for any old received/transceiver I would use one of these Chinese kits that is based on the original DL4YHF PIC controller design. Unfortunately, the original firmware has a major design flaw that was carried over the years and this thread viewtopic.php?f=8&t=391757 address that problem and how to fix it.


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 Post subject: Re: CCI's beautiful frequency counter.
PostPosted: Mar Sun 28, 2021 10:11 pm 
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Joined: Aug Sat 31, 2013 11:16 pm
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Hey Acorn, I want to learn. Can you explain the 10 vs 8 divide by thing and the 100Hz flicker? I know how the basics of a frequency counter works.


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 Post subject: Re: CCI's beautiful frequency counter.
PostPosted: Mar Mon 29, 2021 12:55 am 
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Joined: Dec Sun 06, 2020 9:33 pm
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Location: Waterbury, CT. 06704
ACORNVALVE wrote:
Paul Dietenberger wrote:
Is it still possible to build one to these specifications, or are there unobtainium parts in it?


It uses standard IC's and parts. There would just be the specific crystal. I wonder if they still have the pcb foil patterns.


Don't know if it is the same but this might help:

Attachment:
Torrestronics_Inc.--TK-1--user--ID6119.pdf [1.03 MiB]
Downloaded 149 times


EDIT* Shows how to hook up the TK-1 to different radio's. It does not have a schematic of the tk-1 that I remember.

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 Post subject: Re: CCI's beautiful frequency counter.
PostPosted: Mar Mon 29, 2021 1:11 am 
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Here is the build manual I believe. Have fun!

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 Post subject: Re: CCI's beautiful frequency counter.
PostPosted: Mar Mon 29, 2021 1:42 am 
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6E5 wrote:
Hey Acorn, I want to learn. Can you explain the 10 vs 8 divide by thing and the 100Hz flicker? I know how the basics of a frequency counter works.


According to CCI's manual the flicker is reduced by a divide by 2 initially rather than divide by 10, but the author of the document did not provide the exact reason, it may relate to reduced signal jitter because the cumulative jitter in the initial divide by 10 would be a lot higher than in the divide by 2, but is an interesting question.

One thing though that affects it in use, possibly more, is how often the display is updated between counts. A good rate is around 9 to 10Hz it would seem providing a reasonably long count but fast enough to track a radio's VFO. This way when the counter is connected to something like a VFO, and the knob is manually rotated, it appears to very smoothly follow the frequency, without any obvious delay, which could occur say if the sample time was longer. In any case the effect with this counter overall is excellent.

CCI publish a Mating document, which show how to connect their counter into various radios. The trick I found, for my ZC1 radio, was to do it without de-tuning the radios VFO, the method I used, which also involved some added coax cable (for its capacitance) is in this article on page 70 of this 78 page article:

http://worldphaco.com/uploads/ZC1_MK2_P ... PPLIES.pdf

It was aided by the fact that I had added a pre-amp to the counter's input.


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 Post subject: Re: CCI's beautiful frequency counter.
PostPosted: Mar Mon 29, 2021 1:53 am 
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Joined: Jan Wed 15, 2020 11:29 pm
Posts: 2173
Location: AUSTRALIA
Location: Queensland.
KX5JSC wrote:
ACORNVALVE wrote:
The CCI design was very clever though, especially in one respect and it beats all my other counters, it has no last digit (100Hz) flicker. Somebody at CCI noticed that in most counter designs they start with a divide by 10, but it is preferable initially to start with an initial divide by 2, so they used, after their input transistor pre-amplifier a divide by 8 using a 74LS93.

What kind of radio in the CCI2 photo?

John


That is the New Zealand made ZC1 Mk2 field radio (they were portable ha ha, but in those times people could lift more than a mobile phone). There is a website in NZ dedicated to these wonderful radios. 2MHz to 8MHz transmit and receive, 12V operated from two 6V Lead acid Batteries and an extraordinarily good construction quality, unbeaten for the time actually:

http://www.zc1-radioclub.org.nz/what-is-a-zc1.html


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 Post subject: Re: CCI's beautiful frequency counter.
PostPosted: Mar Mon 29, 2021 2:06 am 
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Joined: Jan Thu 01, 1970 12:00 am
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Location: Oak Creek, WI USA
ttx450cap wrote:
Paul Dietenberger wrote:
Is it still possible to build one to these specifications, or are there unobtainium parts in it?


keeps your eyes on ebay.. you might catch a lower cost FQ counter on there seen many. good luck


Fortunately I won’t have to, since I’ve owned a Fluke 1980A for years, but it occurred to me to wonder whether it could be built again since they’re obviously uncommon.


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 Post subject: Re: CCI's beautiful frequency counter.
PostPosted: Mar Mon 29, 2021 2:17 am 
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Location: AUSTRALIA
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upsss wrote:
ACORNVALVE wrote:
Communications Concepts Inc (CCI), once made a really nice frequency counter, the TK-1. It was designed as an add on typically for tube radios or others, where a digital frequency display would help.

Yes, ~45 years ago that frequency counter was beautiful. In fact around that time, I used a similar design which I wire wrapped and actually squeezed it into my Heathkit HW101 and replaced the entire mechanical dial.

Today if I wanted a digital frequency display for any old received/transceiver I would use one of these Chinese kits that is based on the original DL4YHF PIC controller design. Unfortunately, the original firmware has a major design flaw that was carried over the years and this thread viewtopic.php?f=8&t=391757 address that problem and how to fix it.


I have bought a few PIC/Firmware based counter modules over the years, but none have impressed me as much as the CCI unit, which is simply hard wired logic and independent of firmware.

Not that there is anything wrong with a firmware based design, it is just that the designers rarely publish the code and it could be buggy making it difficult to modify or fix. There is one other thing too, flash memory that holds firmware in a lot of PIC based devices, is actually "forgetory". Nobody is 100% sure how long it will last, could be less than 10 years in some cases or 50 years in others. The thing is though, if you don't have the original file and the ability/gear to reprogram the particular IC, it is game over for the appliance. Its another sort of built in obsolescence.


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 Post subject: Re: CCI's beautiful frequency counter.
PostPosted: Mar Mon 29, 2021 3:12 am 
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Location: Montreal, Quebec
December 1972 QST, I'm pretty sure, had a frequency counter that had programmable counters, so you could subtract the IF frequency.

Others followed, you could also mix frequencies to get the proper display, or just a mixer and oscillator to display 0-500KHz for a rig where the VFI tuned a fixed segment.


Don Lancaster, in his TTL and CMOS Cookbooks shows a synchronizer to get rid of the bobble.

If I was building a frequency counter today, I'd use 74LS390 dual decade counters, and an octal latch like the 74LS374, so four digits would need two ICs plus the decoders. But no programmabikity.


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 Post subject: Re: CCI's beautiful frequency counter.
PostPosted: Mar Mon 29, 2021 4:24 am 
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ACORNVALVE wrote:
Not that there is anything wrong with a firmware based design, it is just that the designers rarely publish the code and it could be buggy making it difficult to modify or fix.

This is DL4YHF's web page with his original firmware source code https://www.qsl.net/dl4yhf/freq_counter ... unter.html. If you are going to use it as a digital frequency display for a receiver (which is what it was originally designed for), all you need is 4 digits and the 100Hz digit will NEVER flicker. By eliminating the 5th digit you can also eliminate that digit discrete driver with its AND diode logic. I have built one of these counters into an RCA WR-50B signal generator on a single 3" x 3/4" prototype board.


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