One Last FM Exciter.

[Zozo]

Update: Ok so I've managed to get a little more done today on the test board, which is coming along slowly. I've only had to cut on track on the bottom to introduce a resistor which is "Dead Bug" fitted to the bottom. I didn't notice the mistake when working on the PCB layout, and for some reason it just didn't twig until I powered up for the first time.

Anyhow it's a simple error and I don't think anyone else following this thread saw it either, or if they did it wasn't mentioned. To put it simply I had the PLL control voltage filter capacitor coupled directly to the Varicap of the tank osc circuit.

The oscillator is now working fine. But I've been having a problem with the Pic programming, so I've had to put things on hold. For some reason it's not programming correctly. I do have an old Velloman programmer somewhere, but for the life of me, I can not find it. So I've had to use the K150.

It could possible be the Pic I have that's at fault, or even the SAA1057. It has been kicking around for a very long time and I know the Philips one's have been known to either go faulty or just simply be "DOA" in the strip.

I've had a quick probe of the 16F84 in circuit and it's seems "when programmed" Pin 3 "RA4" is pulled low, and Pin 18 "RA1" is only 1V, which I'm sure both are not correct.

20210320_185739.jpg

[Zozo]

EDIT: Yes this is my video with the test driver board with some RDS going through it.

[sinus trouble]

I may be a just a Lucky Git as i have not so far had any problems with that PLL?

However others i know have had the odd dodgey PIC?

I use the ancient Velleman programmer you mentioned, But with so many different software versions out there its hard to say if or what went wrong?

It could be a matter of the initial settings? Maybe the OSC or CONFIG word commands missing?

[RF-Head]

Looks like my old driverboard

[RF-Head]

http://www.piratenpraten.nl/schemas/3-m ... %202007V1/

[Zozo]

The similarities between your board and what I've been putting together is almost identical. The funny thing is, I've never seen your board before, which is the gods honest truth. The more I look at it, the more uncanny it is. I mean even the choice to the layout of the PLL IC's and DIP Switches. Not the mention many other areas that are just the same.

I suppose it's the obvious choice when it comes to the layout. Like the old saying "There's only one way to do something, and that's the right way". or maybe when it came to the design, its was the most logical way. Anyhow it's left me slightly gob-smacked with how similar it is.

The RF strip being all straight, with one stage after another seemed the best way to do things, which is more or less the way BW did it. I had a look at the link you shared and one of the pictures even shows you used the free space under the DIP switches to add some text like I have done. We must have a similar mind-set.

[Zozo]

Update: So it would seem that it was the "Philips" branded "SAA1057" had failed. I'm not surprised to be honest, I've seen this a few times over the years. They had a tendency to just fail. I have switched in a "NXP" branded "SAA1057" which is "Bomb proof" in comparison.

The only other revision change has been the addition of the series resister from the control voltage pin of the "SAA1057" that was coupled directly to the oscillator tank capacitor by mistake. (I know, silly school boy error).

I'm very happy with the final revision PCB, which will be making it's was to JLC very soon. Once those have arrived and I've assembled one to test, I'll release the final Gerber files and all it associated information etc.

Bonus: The design in it's current working state would appear to be "No-Tune". This was not something I was aiming for, it's just the way its worked out. You can set the switches for 87.5 to 108 Mhz without having to adjust anything.

[Zozo]

The completed test board with all it's components populated. (Working)

20210323_114706.jpg

[Zozo]

It's DONE! I can finally say complete on this project, which I'm happy to share with you all.

The new PCB's arrived very early this morning, and it's taken almost 2 hours to complete the new board. It's been fully tested and works perfectly.

Although It's complete there is still one more version on the drawing board, which utilizes the newer SMD MRF4427 instead of the traditional 2N4427. It's still in the development stage, but wont take me long to iron out all the wrinkles. I wont bore you all with the details, but instead will just share it as an when its time is ready.

[Zozo]

Complete File Pack Below:

ZoZo-PLL-Mk2.rar

[Zozo]

Finished Look of the MK2

20210401_134832.jpg

[Zozo]

Oh just for fun, has anyone else who uses JLCPCB get their "Free Puzzle" with their order?

I've given it to the XYL to put together

20210401_143257.jpg

[1608cc]

When you put them together you will get coupon code (JLCfactory) with previous orders I got a few insulation tapes and key rings

156962904_240968501022298_4232546564436026551_n.jpg

[rigmo]

when we will stop using 2n4427? pleas... whay you not use RQA0009 4W...

[Zozo]

when we will stop using 2n4427? pleas... whay you not use RQA0009 4W...

Well technical I've stopped using the 2N4427 now, as I'm well on into the development of the MK3 boards. I'm not sure how much demand there would be for a 4W driver? Anyhow this is just a time passing hobby for me. I don't plan on selling the driver boards as I've given it all away for free to anyone wishes to build there own.

Saying that I may just sell the PCB's. I wont be selling completed boards or the required components, as I use them in other designs on bands I'm licensed for. Plus there's an ethical issue too.

I think I know the "RQA0009" which is used in the "Baofeng / Pofung" hand held transceivers. Anyhow they would need a more adequate heatsinking for continuous operation, where as the MRF4427 hardly needs any.

[Zozo]

When you put them together you will get coupon code (JLCfactory) with previous orders I got a few insulation tapes and key rings 156962904_240968501022298_4232546564436026551_n.jpg

No coupon on mine sadly.

[radium98]

thank you @Zozo i wish will this art of beauty have an lcd later

[Zozo]

thank you @Zozo i wish will this art of beauty have an lcd later

Possibly maybe in the future. I would probably have to change the synthesizer to maybe the TSA5511 / TSA5512 instead of the SAA1057, and a header connector where the switches are for the LCD module to connect.

We're see how it goes

[teckniqs]

thank you @Zozo i wish will this art of beauty have an lcd later

"Proper Pirates" don't have LCD frequency displays on rigs....

[Zozo]

thank you @Zozo i wish will this art of beauty have an lcd later

"Proper Pirates" don't have LCD frequency displays on rigs....

Yes I agree Tech, as most pirates don't really regard that as a must have feature. But I can understand that some people do.