RF Head 1w driverboard help

[Albert H]

The 74HC4024 goes (at 5V supply) to around 77 MHz. You can get it slightly higher by running it at 6 Volts (not really recommended).

There is a 74AC4024 that goes to over 120 MHz, but they're more expensive than the whole of the rest of my discrete PLL these days.

The 4024 is ideal for doubler rigs. I explained earlier in this thread why doubling is a good idea. It makes for much greater stability as you can't get the big stages coupling back into the oscillator.

[Bton-FM]

Have you got a doubler circuit or a link to one ?

[Albert H]

Here you go:

B2DriverPLL.png

The coil in the oscillator stage was a Toko S18 white (7½turns) with a ferrite slug, and the doubler and filter coils were Toko S18 yellow (4½turns) also with ferrite slugs. The S18s are difficult to get in the UK, but a few places still stock them.

The original varicaps were BA102, but I've seen reverse-biased 1N4148 used for the modulation and green LEDs for the VCO tuning.
The BSX20s can be replaced with the BF199

The diodes around the 4040 need to be worked out for the frequency you want to use, and take the feed to the 4046 from the most significant diode cathode. The diodes around the 4060 set the divider in the 4060 to give the reference you want. The doubler and filter stages are switched off when the PLL is out of lock, so you can't transmit on the wrong frequency.

You'll get about 20mW of clean Band II out.

[Bton-FM]

Thank you!
I’ll give it a go sometime but first I want to finish the one posted at the top of this thread for starters.

[livendirect]

Cracking boards well worth the money nice audio too

[Electronically]

Dunno if that's the right driver but seems so.

Sent from my AMN-LX9 using Tapatalk

[Albert H]

The 74HCT4024 will go to 110MHz if you run it at 6.2V (the absolute maximum). I use 74F160 these days if I need to divide ~100MHz directly (like for a PLL-controlled Band I receiver)

[MiXiN]

NRG Sells it on ebay as KIT
Mail him for the component layout
He bought the design and Layout from me
I stopped making this design

I managed to get a a component layout for this from NRG on eBay, but some of the values of the Resistors are totally different to what I can see on images of this board ready built.

Do you have any old notes or a component layout around from when you did these, please?

Not sure whether to build with component layout provided my NRG, or copy ready built driver board values!

[LeeCavanagh]

I thought NRG in the UK was long gone & only in New Zealand now.

NRG Chris in the UK is still about doing bits and bobs.

https://www.ebay.co.uk/usr/nrg-electronics

He rarely replies to customers on eBay, dont think he can be that dedicated to actually selling anything to be honest, if you got anything out of him then you were lucky

[sinus trouble]

He rarely replies to customers on eBay, dont think he can be that dedicated to actually selling anything to be honest, if you got anything out of him then you were lucky

I hate to be so brutally honest! This is the problem with Ebay! People expect the cheapest price and a lifetime of technical support thrown in for free! Mr NRG is a busy man just like the rest of us!

Im sure he will help if he can!

[LeeCavanagh]

He rarely replies to customers on eBay, dont think he can be that dedicated to actually selling anything to be honest, if you got anything out of him then you were lucky

I hate to be so brutally honest! This is the problem with Ebay! People expect the cheapest price and a lifetime of technical support thrown in for free! Mr NRG is a busy man just like the rest of us!

Im sure he will help if he can!

You can be as honest as you like, i respect that.
I should point out that each time i contacted him it was with an interest in buying, not for support, but not once have i had any reply