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SO-3 TCXO substitution

Details: Last Updated: Thursday, 16 December 2021 10:02; Hits: 29719

One of the first things that bothered me with my brand new TS590s was a noticeable fequency drift at startup. I was quite surprised to learn that the master clock of the TS590s uses a normal Xtal oscillator at 15.600 MHz.

As a solution, Kenwood is "offering" an optional TCXO, named SO-3. It was another shock when i saw the retail price for a new SO-3. It costs a heavy 130 € in France while a new TS590s can be found around 1500-1600 €...

Nowadays, in all serious rigs a TCXO is a MUST with the growth of digital modes. In mass production, it only costs a very few €uros. I'm convinced that the price of the TS590s wouldn't be higher (or even cheaper) if Kenwood would replace the original Xtal oscillator + the TCXO addon board + 2 jumpers + the 2 connectors + screws, etc... with a TCXO !

But that's certainly a way for Kenwood to make an easy money by selling their optional SO-3 TCXO !

Moreover, the customer has to solder the TCXO on the addon board he has to remove from the transceiver. RIDICULOUS !!

PIC tone decoder

Details: Last Updated: Saturday, 31 January 2015 17:54; Hits: 29268

decoderpic Here is a description of an audio frequency tone decoder build around a PIC 12F683.

For a cost not much higher than a basic NE567, you will have :

- A more efficient decoder
- Far better stabiliy
- A settable threshold with hystereis
- Possibility to tune from 100 to 2148 Hz or use a fixed frequency
- No exotic or particular component

16 LED bargraph.

Details: Last Updated: Thursday, 28 April 2016 20:43; Hits: 18764

In one of my projects, i wanted to use 2 LED bargraphs.
The classical way to do that is to use a IC made for that, the LM3914. This circuit has been build to drive 10 LEDs which are generaly in a single module.
10 LEDs wasn't quite enough for my usage, i wanted more diodes for more "precision". I also wanted to mix diode colours, what is not easy to do with diode modules.