Dawson PLL transmitter

YellowFM · Post by **YellowFM** » Thu Nov 05, 2015 6:00 pm

Hello , someone tried to combine this modulator http://electronics-diy.com/1-watt-pll-f ... mitter.php
and the frequency synthesizer pira cz?http://pira.cz/enpll.htm
Maybe someone has a PCB board in sprint layout?

pjeva · Post by **pjeva** » Thu Nov 05, 2015 7:07 pm

No problem with that, just pick up pll input signal after doubler, not before like in schematic...

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YellowFM · Post by **YellowFM** » Thu Nov 05, 2015 7:53 pm

Actually can you recommend a good diagram of a modulator for my transmitter , there was a lot of typical London pirates schemes , but no circuits and printed circuit boards ( (
It's Commercial Projects ?
I'm looking for a modulator circuit that would collect it himself , preferably with a frequency synthesizer based on the SAA1057.
I live in Ukraine , because I can not buy kits for assembly and for me it is very expensive ..

pjeva · Post by **pjeva** » Thu Nov 05, 2015 10:05 pm

http://www.3-mtr.info/manuals/ELENOS/ETG150UK_1.pdf

Here... Complete one. Just use pira pll with this and it will be fine.

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sinus trouble · Post by **sinus trouble** » Thu Nov 05, 2015 10:20 pm

Hello Yellow!

My exciter pcb uses that circuit and is on this forum if you need a reference?

YellowFM · Post by **YellowFM** » Thu Nov 05, 2015 11:03 pm

Yes, thank you

YellowFM · Post by **YellowFM** » Thu Jan 14, 2016 9:42 am

Shedbuilt · Post by **Shedbuilt** » Thu Jan 14, 2016 2:26 pm

The thread is called Sinus 1watt pll.

YellowFM · Post by **YellowFM** » Thu Jan 14, 2016 2:38 pm

someone has his scheme , and leyout file for it ?
In my country hard to get cmos logic and transistor 2n3553
but there SAA 1057 TSA 5511 and PIC microcontroller , there is also a series of transistors RD 06 , RD15

Maximus · Post by **Maximus** » Sat Jan 16, 2016 2:57 am

YellowFM wrote:someone has his scheme , and leyout file for it ?
In my country hard to get cmos logic and transistor 2n3553
but there SAA 1057 TSA 5511 and PIC microcontroller , there is also a series of transistors RD 06 , RD15

This'll be of use. He did have the eagle file for the pcb but must have removed it. If you ask him nicely, he'll probably send it to you.

http://jugglingpirate.net/1w-pll-fm-transmitter/

EDIT: the files are still on there.

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s2000 · Post by **s2000** » Sat Jan 16, 2016 1:19 pm

There are errors on the juggling pirate pcb, wrong components values etc.. I built it took over a month to sort out what was wrong. If you do build it, you will have no pll lock and very low audio...

radio-berlin · Post by **radio-berlin** » Sat Jan 16, 2016 2:38 pm

s2000 wrote:There are errors on the juggling pirate pcb, wrong components values etc.. I built it took over a month to sort out what was wrong. If you do build it, you will have no pll lock and very low audio...

I just had a look, to make audio much louder use 33k for r1, 1k for r2 and r3. You will lower the voltage to Varicap

Or replace all 3 resistors with around 4k7 and replace vd2 with a 1n (1000pf) so that it increases the swing on the single Varicap.

s2000 · Post by **s2000** » Sat Jan 16, 2016 3:52 pm

radio-berlin wrote:
s2000 wrote:There are errors on the juggling pirate pcb, wrong components values etc.. I built it took over a month to sort out what was wrong. If you do build it, you will have no pll lock and very low audio...
I just had a look, to make audio much louder use 33k for r1, 1k for r2 and r3. You will lower the voltage to Varicap

Or replace all 3 resistors with around 4k7 and replace vd2 with a 1n (1000pf) so that it increases the swing on the single Varicap.

Hi mate, what I found was the varicaps had no ground connection on the pcb (jugglings eagle design) and one of the chips had no ground... Also the cap for the crystal seamed to be wrong value as had no 12.5khz reference for the phase comparator. Luckily I had an old Dawson original board to compare with and work out what was wrong

teckniqs · Post by **teckniqs** » Sat Jan 16, 2016 4:11 pm

They aren't the best design, very outdated with retro parts and the PLL part tends to be quite noisy I found.

YellowFM · Post by **YellowFM** » Sun Jan 17, 2016 7:41 pm

how to connect the tsa5511 or saa1057 to this driver ?
Please draw a schematic , those who had already done .
leave those resistors and capacitors in the circuits of the RF signal , and controls the frequency synthesizer?

shorty · Post by **shorty** » Sun Jan 17, 2016 11:52 pm

@Mr Yellow, if you want to build an fm exciter using the pira pll circuit, why not build sinus's 1 watt exciter it combines the pira pll circuit with the nrg 1 watt driver, Mr Sinus has posted the pcb and component layout with a full parts list on the forum, all the parts are inexpensive and readily available, he's made a cracking exciter that seems to fit your requirements low cost with parts that can be obtained in the Ukraine, i'd give Mr S's board ago over the Dawson.

viewtopic.php?f=11&t=275

teckniqs · Post by **teckniqs** » Mon Jan 18, 2016 1:03 am

I second that, I've used one and it has a very clean output with very low noise.
If a Dawson isn't tuned up properly it can put out some serious nasties and as for the noise, well....

sinus trouble · Post by **sinus trouble** » Mon Jan 18, 2016 10:28 pm

YellowFM wrote:how to connect the tsa5511 or saa1057 to this driver ?
Please draw a schematic , those who had already done .
leave those resistors and capacitors in the circuits of the RF signal , and controls the frequency synthesizer?

Hello Mr yellow

On your diagram, C14 is the sample output! The PLL uses this to monitor what is comming out of your VFO!
UD3 i believe is the tuning side? The PLL will send a DC voltage there to correct any movement in frequency detected! (between 0.5v up to supply V)

Shedbuilt · Post by **Shedbuilt** » Tue Jan 19, 2016 3:11 pm

One thing to note. In the "Dawson board" schematic, the oscillator is running at 1/2 the output frequency, and the sample for the PLL is at the oscillator frequency. I think the software for most of the common TSA5511 and SAA1057 designs, uses divider rates to cater for "at frequency" input, so - if you do want to do this, you should move the PLL sample point. The simplest way would probably be to move it along one stage; the drive to the Base of Q4, should be mostly at the output frequency (if L2 and VC1 are correctly tuned at least). The purpose built PLL chips will also need a lot less input voltage than the 74HC4024, so whereas the "Dawson" board uses only a DC blocking capacitor between the sampling point and the 74HC4024 (C14), you could either substitute this for a much smaller capacitor (probably only a few pF), or if you're using the Pira design, which already has a DC blocking cap (C7 in the Pira PLL tuning unit schematic), you could use a resistor of perhaps a few K, instead of C14 from the "Dawson" schematic. Another way of sampling, might be to split the "Dawson" R13 into two resistors (two resistors in series, to make the same total resistance as R13), and take the PLL drive from the junction of the two resistors. Again, this will need a DC blocking cap before going into the PLL chip, but that is already there in the Pira design.

pjeva · Post by **pjeva** » Tue Jan 19, 2016 11:09 pm

You could also make a small coil very close to output connector or few turns of insulated wire around center pin of connector. Then connect that using coax to the input of pll chip. It will induce enough power to sample frequency for both SAA1057 Pira pll or TSA5511

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