That's promising! Be careful getting rid of the heat from the '1947 - having it in contact with the case might work, but could lead to all sorts of "ground loops". I'd be inclined to use its big "chimney", but see if I could fit it horizontally under the board, with a mica film - still pretty heat conductive - isolating it from the case, and using the case to radiate the heat.... That's another reason I preferred the '1971 - it was easy to mount using a standard TO220 insulator kit!

If you get that collector coil really optimised, you should find that the power goes up a bit, and the current draw should reduce, indicating even better efficiency! Good luck with your experiments.

Incidentally, if you want to add a simple PLL to the circuit, let me know, and I'll give you the circuit that I used.

Very very nice ...Sinus please look the way for heatsinking the 1947 on veroxxxx or NRG 5watt vco .I will put a picture later.need some mechanical work

What make me surprised is 4 or more.output on vco and does not drift?

Some pictures to get inspired for the idea Sinus . I know you know them , just a memory refresh .

Albert H wrote: ↑Sun Sep 25, 2022 5:08 am That's promising! Be careful getting rid of the heat from the '1947 - having it in contact with the case might work, but could lead to all sorts of "ground loops". I'd be inclined to use its big "chimney", but see if I could fit it horizontally under the board, with a mica film - still pretty heat conductive - isolating it from the case, and using the case to radiate the heat.... That's another reason I preferred the '1971 - it was easy to mount using a standard TO220 insulator kit!

If you get that collector coil really optimised, you should find that the power goes up a bit, and the current draw should reduce, indicating even better efficiency! Good luck with your experiments.

Incidentally, if you want to add a simple PLL to the circuit, let me know, and I'll give you the circuit that I used.

Cheers Albert!

Infact i have something similar to the Mica insulators? Those Silicon rubber type ones would probably do the trick!

Thank you It would be interesting to see the PLL you have, Even though i still prefer the "Old Style" of tuning for a bit of nostalgia!

radium98 wrote: ↑Sun Sep 25, 2022 7:05 am Very very nice ...Sinus please look the way for heatsinking the 1947 on veroxxxx or NRG 5watt vco .I will put a picture later.need some mechanical work

Thank you Radium!

I may have to do just that, Fabricate my own custom heatsink? Or add a miniature cooling fan? These are decisions i have to make?

However, Whilst i have the tools and engineering skills? Some others may not?

If i can keep it simple and stay within the limitations of the device? Temperature should not be a big deal!

radium98 wrote: ↑Sun Sep 25, 2022 7:07 am What make me surprised is 4 or more.output on vco and does not drift?

Well now you mention it! It does drift, But only by a tiny amount!

Usually when you first switch on and the transistors are warming up, But after that its really stable!

To put it simply? The 1947 is doing all the heavy work producing the 4 Watts! The VCO is doing the easy work with very little stress!

Stephen Moss perfected this with all his designs! His 1 Watt VFO stability was phenomenal!!

Cheers.

So!

Here is the first draft of the "Sinus B1 PA" The PCB is of similar dimensions to the "Sinus B1 VFO" and should allow direct interface for those who wish to upgrade!

Again! This is experimental and will be subject to change when Necessary!

ATTENTION!!!

I will have to hold fire on this project! Some supply issues have changed which will affect production!

I will continue to look for alternatives? But for now its on hold!

I take it that would be the 2SC1947 ?

Bazz wrote: ↑Sun Oct 02, 2022 11:06 am I take it that would be the 2SC1947 ?

Correct Bazz!

However i am pleased to announce that Enigma have updated their stock levels!

I will have to put in my order this week to be sure? But it looks like all systems go!

I may add an optional TO-220 Footprint to the PCB? Lets see how it goes!

We patiently wait.

Apologies for the delay, I have been out of the country on Business!

I was not happy with the first design so i made some small changes!

I think this will be the design i go with?

good to see that Sinus.

Hello! i'm looking for the files (hex, etc...) to download and start a sinus rds project at home can anyone send me the link please?

Hello Obdbeats

Link above! You will need to install the software onto your PC

Once installed, Open the program and there will be a Question Mark in the top right of the screen! (?)

Click on the folder labelled "Firmware" Which contains the file "PIC16F628.Hex" (Stand alone)

Pre-program the PIC with this file before inserting into the SINUS RDS PCB

Good luck!

If you want to phase-lock your Band 1 rig, here's a cheap and simple way to do it:
The reference frequency from pin 1 of the 74HC4060 is 1 kHz, so you divide your oscillator frequency down to (nominally) 1 kHz with the programmed 74HC4040. Remember that the oscillator frequency will be half of the output frequency. The LEDs can be a single common cathode bicolour type (usually Red & Green) and then out-of-lock is Red, and locked is Green.

This simple synthesiser can use another frequency crystal, by using the same programming trick (as used on the 74HC4040) on the dividers in the 74HC4060 - connect its Reset pin to the positive rail through a 4k7 resistor, and then use diodes to select the outputs you need. Take the reference frequency from the cathode of the MSD diode (like with the 74HC4040 divider), and then this will allow the use of cheap 4MHz crystals (for example). The diode programming trick works by resetting the counter when all the diode cathodes go "high" simultaneously (when the required count is reached), so the counter starts again from zero. The reset pulses are very short, so can't be used to feed the 74HC4046, which is why you'll take a nice, wide squarewave from the cathode of the "Most Significant Digit" diode.

Two notes - you can't use the ordinary CMOS ICs - you must use the faster 74HCXXXX types for it to work at these frequencies, and the loop control voltage may need to be amplified (and perhaps further filtered) by an op-amp stage.

Pin 9 of the 74HC4060 gives the crystal frequency - good for trimming the reference frequency.
The lock detector works well. I use a couple of cheap 2N3904 and 2N3906 transistors.

Thanks Albert . I am sure sinus will do good job for all who dreamto make a complete 4w Stl link . Thank you guys for efforts you put .