#962

[@charlescartwright6367]

Aloha, I'm old and started my electronics on tubes, we were told transistors would never amount to much as the were noisy and couldn't handle power that was back in the late 50's. My highlight was when they put B+ on the grid caps, broke me of the habit of licking my finger and scratching the grid of a stage!!!! I very much look forward to your SMT techniques. I love retirement but you gotta stay busy... use it or loose it!

[@MUHAMMADYAWARIFRAHEEM]

Very informative video Sir

[@riccardopapi5992]

For the VCO to generate a stable frequency, you need to have a phase comparator and a charge pump to drive it. There should be a reference frequency generator with a programmable divider to drive one leg of the phase comparator. All of this circuitry, if I am not wrong, happens to be in the PLL unit you are getting rid of. If you simply drive the VCO with a variable voltage, without any feedback, the VCO will drift a lot. Am I missinig something ?

[@IMSAIGuy]

I will be adding a frequency counter later for the feedback

[@bobkozlarekwa2sqq59]

I’m very impressed.

[@caulktel]

Im really loving this build.

[@Dennis-uc2gm]

Very interesting. I've got an old IC-211 that needs something like this to bring it back to life.

[@stephenstebbing9460]

Yes, please on the surface-mount video.

[@mrbambix]

what a great project to bring the 245 into current times, very informative. thank you for this series.

[@Seth7Seth7]

Keep at it ... I haveva 245 with the ssb addition

[@rjordans]

Nice idea! I like the extension headers built in but for next time I would suggest to and include some power and ground line in there to really make it a one step plugin. For the reduced range on the dac, I believe the datasheet also has a note on how to use this as a window dac. Looking at how you're using it here you may be able to reduce the circuit the to two resistors and no extra reference. You could do a 4k from dac to output and a 1k from output to 5v. Together these make a divider where you lift the bottom end to increase the output voltage. The opamp may still be nice to have as buffer it there's any loading on the circuit

[@CalebSkurdal]

This is really cool! This is good idea to take old rigs and modernize with Arduino (or my favorite Micro/CircuitPython)

[@rfburns5601]

I pulled out the 245 today, sure enough the vco is stuck at 135 mhz - does not change with tuning - no transmit power. Will try variable dc to vco to see if I can get it to receive at 146 mhz. Was able to get 10.7 mhz fm to pass through. If I can get it to recieve, will short PLL lock/ transmit inhibit line, and see if it will make some power.

[@rfburns5601]

That is extremely impressive! I'm such a hick, that I'd prolly bodge the front panel with 10 turn helipots to run the vco for tx and rx, and a front panel LCD frequency counter with programmable if offset. I do plan to check out my 245 over the holiday and see how bad it is.