SINUS B1 PROJECT

[sinus trouble]

B1 RX SETUP.zip

[sinus trouble]

Above is my first draft of the setup proceedure!

It is in wordpad format! If it does not display? i will try some kinda PDF maybe?

[sinus trouble]

I Hope the instructions are helpful? I wanted to keep it short and to the point instead of rambling on!

Sometimes i may overlook certain details thinking they are obvious? So if anyone feels i have missed something? Let me know!

I will update the instructions!

[XXL]

Thanks sinus.

Iv got a query. This part on your design doesn’t make sense to me. The 2 coils are connected together on the IF can. When I did this I lost the static noise like it’s shorted or something. I noticed they’re connected on your pcb aswell.

[sinus trouble]

Haha! Yes Good point XXL

The Quadrature TOKO actually only has one coil! connected between Pins 1 & 4 (Diagonally across the can)

The symbol used on the schematic is just a generic footprint that i made for a TOKO

By adding extra connections, You are effectively shorting out the coil! Do not add any more connections!

Whilst on the subject of TOKOs Take Notice of the orientation of the I.F. coil! The 3 Pin side should be facing C8! The 2 Pin side is the output and should face C9!

[sinus trouble]

Its great to also hear that you seem to be making some good progress XXL

The fact that you mentioned White Noise is defo a good sign!

Again! The small details that i may deem as obvious? Is not always true for other builders! So i really appreciate your feedback!

[Albert H]

I think that I've got some link receiver PCBs around somewhere - if I can dig them out (when I'm back at home) I might Ebay them for ~£5 each. They're a bit more complicated than Sinus' circuit, using a crystal oscillator, RF preamp, DGFET mixer, a couple of 10.7 MHz stages with transistors and a CA3089. The board also has carrier detect switching and provision for a tone decoder for access too (which stops people "borrowing" your gear by jamming your link). The boards are about 14cm X 8cm and double-sided and silk-screened.

I'll put the circuit (and the PCB layout) up here if anyone wants to make them themselves. The receiver is fully noise-quietening at just over 1.2µV signal, and they have good image rejection. These have been used on Band I and Band III and some are in daily use for radio microphones used by News TV crews. They were designed to fit a standard Eddystone box, and include a power regulator so any DC Voltage over 15V fires them up (we used to power them from the 28V PA supplies).

I'll be home next week, and will let you all know.......

[sinus trouble]

I think that I've got some link receiver PCBs around somewhere - if I can dig them out (when I'm back at home) I might Ebay them for ~£5 each. They're a bit more complicated than Sinus' circuit, using a crystal oscillator, RF preamp, DGFET mixer, a couple of 10.7 MHz stages with transistors and a CA3089. The board also has carrier detect switching and provision for a tone decoder for access too (which stops people "borrowing" your gear by jamming your link). The boards are about 14cm X 8cm and double-sided and silk-screened.

I'll put the circuit (and the PCB layout) up here if anyone wants to make them themselves. The receiver is fully noise-quietening at just over 1.2µV signal, and they have good image rejection. These have been used on Band I and Band III and some are in daily use for radio microphones used by News TV crews. They were designed to fit a standard Eddystone box, and include a power regulator so any DC Voltage over 15V fires them up (we used to power them from the 28V PA supplies).

I'll be home next week, and will let you all know.......

Yes please Albert! They would be great to see!

I also have a theory which i want to test on my Receivers? A stand alone system using a single potentiometer to simply do all the tuning!

The idea is to replace the trimmer caps (C6,C7) and the local oscillator tank cap (C1) with varicaps!

If successful? Both local oscillator and input filter would tune in sync!

This would also allow your Tracking system to be implemented too!

Just a thought for the moment?

[XXL]

Sinus is your board you show built the same as the gerba you posted ? Because it’s shorted on the gerba aswell so not sure how yours is working.

[sinus trouble]

Sinus is your board you show built the same as the gerba you posted ? Because it’s shorted on the gerba aswell so not sure how yours is working.

I can confirm that the PCB files i uploaded are the ones i use!

I know the PCB may look confusing? But i will try to explain!

The TOKO KACSK586HM (Quadrature coil) has a single coil connected between pins 1 and 4!

Pins 2, 3 and 6 are not connected to anything!

The "Shorts" or tracks you refer to are to connect with C12 which is the capacitor which resonates with the Quadrature TOKO coil

Heres a pic below!

Quad Pinout.PNG

[sinus trouble]

Just to add!

Enigma have now introduced an alternative to the KACS3915A!!! (IF Coil)

The KACSK3892A!! So grab it while it is still available!

KACSK586HM (Quadrature coil) Is also in stock!

Good luck Builders!

[sinus trouble]

Been doing some simulations!

I have looked at the spectrum with and without the Low Pass Filter included! Comparisons below!

[sinus trouble]

This is the Sinus B1 TX without LPF fitted!

B1 No LPF.PNG

[sinus trouble]

This is the Sinus B1 TX with LPF fitted!

B1 Inc LPF.PNG

[sinus trouble]

As we can see in the first image, The 2nd Harmonic is quite strong!

Once i added the LPF to the schematic and run the simulation again! Spurs seem to be considerably lower!

Happy Days!

[sinus trouble]

Here is a diagram which may aid those who wish to build a Band I LPF!

Band I LPF.png

[mpx]

Most splendid work Mr Sinus!

[sinus trouble]

Most splendid work Mr Sinus!

Cheers MPX

The simulations are surprisingly accurate to the real thing! However it does not take into account derating of the coils due to proximity to ground plane!

You could experiment with L1,2,3 each being 5 turns x 10mm diameter! This would tighten up the roll off! increasing attenuation of the harmonics!

[radium98]

sinus how did you see the curve of the filter and is it wide band , from wich to what frequency ?

diameter of the copper wire ? 1mm or 1.2

[sinus trouble]

sinus how did you see the curve of the filter and is it wide band , from wich to what frequency ?

diameter of the copper wire ? 1mm or 1.2

Hello Radium!

If you look back at my previous posts, The filter is simulated in LTSpice setup for AC Analysis! The response curve is shown in the top half of the screen (Filter shown below) The test frequency is set from 40Mhz to 150Mhz

1mm or 1.2mm is fine! Its not too critical at such a low power!