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Re: nrg kit pll

Posted: Thu Aug 30, 2018 10:56 pm
by sinus trouble
Hello Mr Radium
As Mr NZ stated, it is hard to understand what is going on with just images!
Also where are the rest of the RF stages and how are you terminating the oscillator??

I had a quick glance at the schematic and your lock status comes from IC3 (74LS86) via R56 and D7
The lock/unlock LEDs should not effect the PLL? But will cause the OLPD section to malfunction!

However IC3 is also responsible for the PLL loop voltage which corrects the varicap!
There is a simple way of checking that your PLL is tracking the tuning! A voltage can be measured on the base of TR1 which should rise up or down whilst very carefully adjusting VC1?

I will try to dig out my NRG over the weekend and take some measurements
Good Luck!

Re: nrg kit pll

Posted: Thu Aug 30, 2018 11:16 pm
by radium98
Thanks sinus i have changed all the ic same result .the lock green led always on .bc558 and 548 are genuine not the fake chinese .i have doubt with the 1n4148 orientation or any capacitor leak .i can test the frequency till the prescalet fleep floo 74als74.and tge crystal oscillator 6.25khz.but i have remarked that if i out my hand on the xtal around tge 4060 the green led flactuate and i can hear on the receiver that the pll is trying to lock.one signal then is missing as a conclusion.
Thanks for the help.

Re: nrg kit pll

Posted: Fri Aug 31, 2018 12:00 am
by sinus trouble
No worries Mr Radium
I don't believe you components are fake or fitted incorrectly!
What range is your frequency counter? From the BF245s (TR4 TR5) you should be getting half frequency?
Depending on your DIP settings? IC3 will output a DC voltage to your varicap (VCD1) and will change if you adjust VC1! If this is the case? then you know the PLL is working and the problem lies in the LED lock section!
If the varicap voltage does not respond to your adjustment of VC1 then theres a problem!

Re: nrg kit pll

Posted: Fri Aug 31, 2018 4:31 pm
by radium98
my frequency counter is up to 1ghz.
from the bf245b i have the half frequency ,lets say i am on 100 mhz ,i measure there at the out that is going to 74als74 50 mhz.
for the other next i will try to see if the voltage varie on the 1310 varicap i also tried bb204 that i have 1 piece.but i dont think that the voltage varie from the 74ls86 ever if i slowly turn the trimmer of the vco to near frequency like on the vero... board , i need to get clarified about the bc transistor used with orientations and the diode zener and 1n4148.
I will try to dig out my NRG over the weekend and take some measurements
Good Luck!
thanks for all the help to guet it work out.

Re: nrg kit pll

Posted: Fri Aug 31, 2018 10:47 pm
by sinus trouble
Heres a pic which may help
20140316_170704.jpg
And schematic!
NRG ProIII Schematic.JPG

Re: nrg kit pll

Posted: Sun Sep 02, 2018 8:01 am
by radium98
where is the schematic ?
Heres a pic which may help
The attachment 20140316_170704.jpg is no longer available
And schematic!

anyway thanks Sinus trouble

Re: nrg kit pll

Posted: Sun Sep 02, 2018 10:21 am
by shorty
I looked at your photos, the diodes / transistors look to be fitted the right way round, your parts placement looks ok, this is the silk screen layout, parts list & schematic, you need to check every part against the list and layout, it should fire up if all parts are ok.

Re: nrg kit pll

Posted: Sun Sep 02, 2018 10:47 am
by RF-Head
Can you make a picture of the SIL resistors next to the 4059?
Maybe they are mounted the wrong way

Re: nrg kit pll

Posted: Sun Sep 02, 2018 5:20 pm
by radium98


thanks you for every one and every help .
My bad it was a shorten 1n4148 and a very critical resistor instead of 18k i have putted 15k strange for that .
Now later i will do the coils and fit the power transistor and lets you know.
Oh very clean audio ,i Love its audio quality .
thanks aGain

Re: nrg kit pll

Posted: Sun Sep 02, 2018 5:22 pm
by radium98
forget to say i have further to drift pitch the xtal a bit i will add a little trimmer because i always have a 98.15 98.35 always 0.5 a 50khz step PLUS.

Re: nrg kit pll

Posted: Fri Sep 07, 2018 8:29 pm
by radium98
tuning aid .

Re: nrg kit pll

Posted: Fri Sep 07, 2018 8:30 pm
by radium98
21768731_10212094445690593_5849866086351328704_o.jpg
tuning aid .

Re: nrg kit pll

Posted: Mon Sep 10, 2018 1:10 am
by Albert H
OK folks. Stephen and I wanted to make alignment of the VCO trimmer capacitor as easy as possible, so this is the circuit that I came up with:
Tuning_Indicator_tidied-V2.png
When both LEDs are off, the voltage at the input (emitter of Tr1 on the PLL Pro III board) is 3.2V +/- 0.75V. You set the switches for the frequency you want, then rotate the VCO trimmer capacitor slowly until both tuning LEDs are off.

Re: nrg kit pll

Posted: Mon Sep 10, 2018 9:42 am
by radium98
I was using it as an aid to find center lock in vero.... board .it seems to be a simple comparator .but tuning is very sharp.thanks for the brillant idea .this board abose is the design of you albert.

Re: nrg kit pll

Posted: Fri Sep 29, 2023 7:11 pm
by radium98
if i can ask , if i want the leds in the tuning indicator to turn off at a voltage of 4.1 or 4.2v what i should made ?

In another way instead of 3.2v i need 4.1 or 4.2v from the regulated 5v source to compare with another 4.2 so the volatge devider may need slight values , what could be thoses values then

Re: nrg kit pll

Posted: Sat Sep 30, 2023 4:22 am
by Albert H
radium98 wrote: Fri Sep 29, 2023 7:11 pm if i can ask , if i want the leds in the tuning indicator to turn off at a voltage of 4.1 or 4.2v what i should made ?

In another way instead of 3.2v i need 4.1 or 4.2v from the regulated 5v source to compare with another 4.2 so the volatge devider may need slight values , what could be thoses values then
If you use 2k2 to the 5V supply, and 10k to ground, you'll be very close to 4V1 at the junction. Another solution would be to buy a 10-turn 10k preset, and tweak it for eactly the voltage you want!

Re: nrg kit pll

Posted: Sat Sep 30, 2023 11:59 am
by radium98
Thank you Albert .I know it was a noob question and that's no good for a person like me .who have some rfknowledge.
An extra question .I bought months ago a tinysa spectrum for my hobbie and as my money can afford , thanks for the new technology. I would like to have a rigol but at the moment is enough .i don't have an rf sampler .if i mount a trap like 40db with an extra attenuator , could i directly measure inline with 60w transmitter .

Re: nrg kit pll

Posted: Sun Oct 01, 2023 3:45 am
by Albert H
You could, but it might be risky - any slight fault with your improvised coupler could fry the input stage of the TinySA!

The way I improvised a coupler (years ago) was to assemble a small diecast box with two N-type sockets and a BNC socket mounted on it. I them had a piece of coax connecting the two N-types together (but with the braid grounded at only one end). My "sniff" loop was a piece of sleeved wire pushed into the coax braid at one end of the link, and emerging at the other. One end of the "sniff" loop was connected to the point at wich the coax braid was grounded, and the other went to the centre pin of the BNC. This crude assembly would give me a reasonable signal out of the BNC for my SA (or absorbtion wavemeter in the earliest days) without risking the PA I was testing or the measuring instrument.

Later testing (with a Time Domain Reflectometer) showed that the discontinuity "bump" (ie: Impedance Mismatch) in the crude coupler was insignificant!

Re: nrg kit pll

Posted: Thu Oct 05, 2023 12:43 am
by LeeCavanagh
Albert H wrote: Mon Sep 10, 2018 1:10 am OK folks. Stephen and I wanted to make alignment of the VCO trimmer capacitor as easy as possible, so this is the circuit that I came up with:
Tuning_Indicator_tidied-V2.png

When both LEDs are off, the voltage at the input (emitter of Tr1 on the PLL Pro III board) is 3.2V +/- 0.75V. You set the switches for the frequency you want, then rotate the VCO trimmer capacitor slowly until both tuning LEDs are off.
Is this what the 3 pin plug marked tuning indicator on the pll pro goes too? Been wondering for some time what that was as never seen it in yse

Re: nrg kit pll

Posted: Thu Oct 05, 2023 1:50 am
by Albert H
Yes. It was my design. There's another version where the two LEDs have to be equally lit, but I found that it was easier to see them go out!