Alberts revised pll?

[s2000]

Just wondering if anyone might of saved that revised Albert H pll circuit diagram that was on the forum before it got hacked?

I saved it to my pc but unfortunately windoze froze one day and I couldn't recover it so ended up reinstalling the C drive

It was the one with the logic ic's, I'd like to have a go at building it

[yellowbeard]

Is this the one you mean? No loop filter on it mind!


http://www.iol.ie/~yellowbeard/AH_PLL.png

[Albert H]

Moral? NEVER use Windoze!

Also - avoid Apple: cheap 'n' nasty hardware in shiny boxes with a corrupted version of BSD with abysmal security!

Linux is the only choice these days. If you're a beginner, try Mint - it's easy to install, comes with all the codecs pre-installed and Just Works™

[s2000]

Thanks guys, that's the one, I will get that built soon.

I did try and run Linux once, around the time windows stopped supporting XP. It looked like the bees knees when it was installing but for some reason it didn't run nice on that particular pc. Maybe not powerful enough for the requirements.

Got a new pc now will give Mint a try too

[3metrejim]

The circuit was based on one of Albert's posted band 2 link pictures and his descriptions of his cheapest pll. There is an error on the diagram on this page, pin 12 on the 4060 (_cko) should be pin 10 - I always seem to make at least one mistake on most things. Bear in mind that it is a half frequency pll. There is no loop filter shown, as the circuitry depends on the characteristics of the vco - control voltage range and sensitivity (KHz per volt on the tuning line).

Here is a pic of a very messy test set up, just to see if it worked.

[Albert H]

I always built them on etched PCBs - after the first few "dead bug" prototypes!

AH_PLL.png

This is the fixed version

[Albert H]

By the way - I always used an active loop filter, usually using a TL072. The first stage would be a twin-T filter at the reference frequency (to get rid of any residual ripple), and the second would be a DC scaling amplifier to get enough swing to tune the VCO. The very last versions of these used a little SMPSU to get 30V for the varicap control voltage, so I could tune right across the band without adjusting the VCO core!