One Last FM Exciter.

[Zozo]

Ok so I've decided to build an FM Exciter for old times sake. This was because as mentioned in another post I have one last SAA1057 kicking around which I found this morning. I'm using Sprint Layout 6 as it's the only PCB software that I'm somewhat able to use without any problems.

I don't like posting half baked projects / schematic etc, but I though I'd just share my progress. I'm not very quick it would seem as this has taken almost 2 hours and I've not even started on the RF section. I'm sure a few years back I would have done that in less than half the time.

Anyhow here it is. possibly may have an error(s)??

DL PCB2.png

[Electronically]

Ok so I've decided to build an FM Exciter for old times sake. This was because as mentioned in another post I have one last SAA1057 kicking around which I found this morning. I'm using Sprint Layout 6 as it's the only PCB software that I'm somewhat able to use without any problems.

I don't like posting half baked projects / schematic etc, but I though I'd just share my progress. I'm not very quick it would seem as this has taken almost 2 hours and I've not even started on the RF section. I'm sure a few years back I would have done that in less than half the time.

Anyhow here it is. possibly may have an error(s)??

DL PCB2.png

Looks OK so far. Instead of the dip switches you could replace that area for lcd display which leads to the pic ic chip that you have there.

Sent from my AMN-LX9 using Tapatalk

[Zozo]

Ok so I've decided to build an FM Exciter for old times sake. This was because as mentioned in another post I have one last SAA1057 kicking around which I found this morning. I'm using Sprint Layout 6 as it's the only PCB software that I'm somewhat able to use without any problems.

I don't like posting half baked projects / schematic etc, but I though I'd just share my progress. I'm not very quick it would seem as this has taken almost 2 hours and I've not even started on the RF section. I'm sure a few years back I would have done that in less than half the time.

Anyhow here it is. possibly may have an error(s)??

DL PCB2.png

Looks OK so far. Instead of the dip switches you could replace that area for lcd display which leads to the pic ic chip that you have there.

Sent from my AMN-LX9 using Tapatalk

Thanks Electronically, I may or may not do the LCD Idea. It's just really something to pass the time and use up the SAA1057. When It's done I'll put the PCB files up for download if anyone wants them. I'll probably just give the board away after I'm done as well.

I've got to the RF section, I wonder if anyone can guess the design by the all parallel resistors H.I

DL-PLL.png

[Zozo]

It's finished (well bottom side) only taken me most of the day , but the bulk is done. Just the top ground plain layer with the through hole links to the unconnected ends on some components.

DL-PLL2.png

[Bton-FM]

Why don't you redo the RF section's layout to make it more efficient? Having all those resistors in a neat line looks pretty, but it means that the tracks between each component are going to be longer. Especially the Oscillator coil - That's miles away from the the oscillator transistor!

The decoupling on the regulator's looks a bit sparse as well, maybe add some 10nf or 100nf capacitors on either side of each regulator?

Can you write code? If so maybe consider replacing the PIC with something more economical. If you don't mind doing away with the dip switches and having the frequency hard coded (or buttons to select the frequency), you could do it with an 8 pin AVR for 30p! PICs are powerful microcontrollers, but this application isn't demanding in the slightest, so it's just a waste of a big micro IMO.

Other than that, this is nice idea to marry the 'Pira PLL' and the BW RF strip. This would make for really cheap driver boards if the MCU was changed. The SAA1057s are all over Ali'!

EDIT: What I wrote about the PIC is probably irrelevant to you since you are doing this as a one off!

[Zozo]

I think one of the other goals was to make the whole thing as small as possible "credit card size" but I think its just over that size now. It was fun to pull up the PCB software and have a play with designing something which I haven't dabbled in for many years. Yes all understood with perhaps changing either the synthesizer or the the PIC and switches for an OPT style board.

Yes some of the tracks maybe a little bit longer to achieve the neatness, but It's better than some of my 1980's spider wiring / birds nesting designs I've built, which still worked "H.I."

I'll have the PCB manufactured after I've checked a few more times to see if it's 100% error free. I think it's close to that now. I had trouble trying to find the Macro for the screened toko's. I thought I had one, but I managed to work around that.

Here's the finalized design that I've fully checked over at least 3 times now. I started to get a bit cross eyed by the end of the 3rd time, I also spent a while hunting round for all the through-holes for the top layer ground plain.

I'll put up all the PCB files for download and people can chop and change it as they please.

DL-PLL1.JPG

[sinus trouble]

Haha! dont worry how long it takes to design.

I spend many hours on my designs (Not all in one go) Its good to take a break and clear the mind!

Getting it right will save money and headache later!

[sinus trouble]

You can also add a lock LED if you wish?

Its not a stable as the usual lock indicator which has its good and bad points?

I have used a similar thing many times and even flickers if you overmod so could be useful?

0_1209322208.jpg

[sinus trouble]

Heres a sneak preview of a 'New' version of the SINUS PLL

SINUS 1W PLL.PNG

[Zozo]

We're all busy making PCB designs for FM Exciters I recognize that PLL and the RF section and it's looking good, I see you've reduced the foot print of the PCB too.

All noted on the Lock Led circuit. I'll see if I can squeeze that in, but its a bit congested on the PCB design I've developed.

What's your choice of PCB software??

[sinus trouble]

No worries!

The lock LED is not really important, The circuit will behave as it should if it is working!

I use EDA software co s it is linked to JLC which makes things simpler, but they are all very similar.

You could move a few components around to shorten tracks? But good so far!

The good thing about that design is that it 'cascades' nicely from one component to another, especially in the RF section!

[thewisepranker]

Why don't you redo the RF section's layout to make it more efficient? Having all those resistors in a neat line looks pretty, but it means that the tracks between each component are going to be longer. Especially the Oscillator coil - That's miles away from the the oscillator transistor!

Completely agree. I see a lot of boards designed like this and it pains me.

[Zozo]

Completely agree. I see a lot of boards designed like this and it pains me.

Valium? No all jokes aside "no pun intended" I think to put this into the old "cross evaluation equation" It will still come out with one resulting answer, "Being." It's probably not worth any more of my time and effort in making alterations. It's basically comes down to "will it work" Yes, Is there "efficiency losses" Yes, as no electrical system in any application can achieve 100% efficiency

I suppose it doesn't help that the image is presented somewhat LS to it's actual size, which makes it look as if there's supper long tracks to each coupling stage in the series RF string. It's not as if there's much inductive aspect being that length, or resistive. Even close capacitive coupling to the top ground plain layer is insignificant really, being as it's such a small value.

EDIT: It was stated at the very beginning, it's just something to pass the time and ultimately will just be given away for free.

[Zozo]

No worries!

The lock LED is not really important, The circuit will behave as it should if it is working!

I use EDA software co s it is linked to JLC which makes things simpler, but they are all very similar.

You could move a few components around to shorten tracks? But good so far!

The good thing about that design is that it 'cascades' nicely from one component to another, especially in the RF section!

Ok EDA, yes I suppose it makes life easier if your using JLC then. I probably won't do anymore to the design in all honesty, well apart from any serious error's. It'll soon be "open source" for anyone to do as they please.

[Zozo]

If anyone wants the Gerber files, there's a link below. Should never expire, unless your reading this post some time way in the future and the admin has performed some house keeping. "H.I."

I did make one last change to all the component hole sizes and centered some of the labeling.

BCWPIRA.zip

[LeeCavanagh]

Thanks zozo

[Zozo]

No worries, Just to note that's for anyone wanting to import it into a PCB design software to make changes. If you want the Gerber files that are ready to be manufactured. You need these below.

Ready to go Gerber files. Plus it includes the Sprint Layout 6 Project File.

BCWPIRARDY.zip

[radium98]

good work guys

[Zozo]

good work guys

Thanks Radium, it's still in working progress, but I've been sharing it as I go. There's all the files for people to play with the design and even chop bits in and out if they wish. I must of checked over the layout more than 20 times now, and I'm sure its 100% error free. Hopefully if someone sees a problem they will let me know.

Here's a bottom plus through hole and labeling layout view.

BCWPIRARDY3.JPG

[radium98]

i wish if it was 4 watts 2n3866 2sc1947 or mrf237 alll in one plate , is true 1w . did you made a prototype .