I guess it is a question of what you are looking for?
I generally as a rule of thumb go for the supplier who can supply quality and not price! I perform many repairs on customers equipment, mainly audio based.
I need to know that the parts i fit will work first time! Every time!
True but not looking for anything at moment but when I do I'll be on egnima
Sent from my AMN-LX9 using Tapatalk
Re: SINUS B1 PROJECT
Posted: Sat Aug 15, 2020 3:50 pm
by radium98
wonderful work sinus keep things up ,but i have a little question how you connect the aerial for reception.you tap the coil ? and in the case of interference it does need for a little cavity filter i think.ove youre diy work
sadly i cannot find thoses toko ,only the one that fit the demodulator ic ,but the coil for mixer can be done with how much turns,from an old can of an AM radio ?
Re: SINUS B1 PROJECT
Posted: Sat Aug 15, 2020 4:04 pm
by radium98
Anyways i will try to put a video together sometime? I dunno which format? but i will see what Radionecks will allow?
put on youtube and delete later or put in private.
The IF coil and Quadrature coil were hand wound on 'Skeleton' formers! Thankfully Enigma had the correct TOKO components to save me from this labour intense process!
a question to be clear the quedrature is onle between two points to get the maximum demodulation and resonate on 10.7 mhz ?
the if what should be between 1 and 3 ,4 and 6 is also keep to pass oly the if 10.7
Re: SINUS B1 PROJECT
Posted: Sat Aug 15, 2020 11:07 pm
by sinus trouble
Hello Radium
That is correct, The IF transformer (centre of PCB) has a primary winding in parallel with a 51p capacitor which resonates @ 10.7Mhz The secondary winding is the output
The Quadrature coil (above CA3089) is a single winding and will need a 82p - 100p capacitor connected in parallel to resonate.
And yes that affects the audio.
Re: SINUS B1 PROJECT
Posted: Sat Aug 15, 2020 11:20 pm
by sinus trouble
20200521_172428.jpg
Re: SINUS B1 PROJECT
Posted: Sat Aug 15, 2020 11:34 pm
by sinus trouble
As you can see, You can wind your own coils
IF transformer = 10 turns primary. 3 turns secondary on 5mm diameter former approx. (C8 will need to be used for resonance)
Quadrature coil = 20 turns on 5mm diameter former approx.
I must warn you in advance! These are approximate dimentions! Fitting the shield case will severely derate the inductance!
I suggest that you do a test wind, measure the inductance and compensate with more turns.
I also modelled this in LTSpice which can also be a great help!
Good Luck
Re: SINUS B1 PROJECT
Posted: Sun Aug 16, 2020 4:37 am
by Albert H
radium98 wrote: ↑Sat Aug 15, 2020 3:50 pm
wonderful work sinus keep things up ,but i have a little question how you connect the aerial for reception.you tap the coil ?
According to the note on his diagram, he taps the input coil 1½ turns up from earth for the aerial input. It'll work, but the sensitivity won't be spectacular.
I used to use dual-gate FETs in my receivers - the extra gate can be used for mixer injection or for gain control. I'll scribble up my circuit, and see if I can locate the PCB artwork. I also used a sophisticated PLL demodulator at the back end of the CA3089 IF chip - this gave an extra bit of sensitivity, and would excavate weak signals from noise! The PLL demodulator is subject to a Patent (look it up if you really want to use it), so I won't post it here (until the Patent expires in 2024).
The front end really works well, and if sensibly constructed will be sensitive, stable and selective, and doesn't suffer from de-dense problems in proximity to big rigs. I'll get scribbling shortly.
Re: SINUS B1 PROJECT
Posted: Sun Aug 16, 2020 6:56 am
by radium98
Thank you very very much @sinus .
@albert thank you for the valuable infos ,a question ? do you think you and we will be alive till 2024 .I will not say more .
Re: SINUS B1 PROJECT
Posted: Sun Aug 16, 2020 9:10 am
by radium98
20191121_151256.jpg
i dont find any of thoses but have a double circuit ,one have the if coil andone the quadrature i think ,because it was fitted a 22uh and ca3089 i have remove it .will try later .
Re: SINUS B1 PROJECT
Posted: Mon Aug 17, 2020 3:07 am
by Albert H
This is the "front end" I used to use on Band 1. I found that it was useful to be able to vary the input amplifier gain. Sometimes, I'd use a double-tuned filter on the input, with a split capacitor as the antenna feed point - it avoided tapping the coil.
Link RX Front End.jpg
Back in the 80s, I mostly used the "Ambit" IF boards - they were cheap and gave great results, and were a bit of a time-saver. I'd build 20 of them at a time, so that I always had stock. I'd usually add an RSSI-driven relay, so that carrier presence could be used to switch the main rig. Also often I'd add a pair of NE567 tone detectors and a bit of logic, so that the main rig was started up with a tone-burst, then sustained by the RSSI. Dropping the link carrier would then shut down the main rig at the end of a broadcast. This prevented numpties from "borrowing" my rigs when they were not in use!
One thing I've missed off the scribble - there would usually be a pair of switching diodes connected between the first FET input gate and ground, to provide a measure of static protection.
Re: SINUS B1 PROJECT
Posted: Wed Aug 19, 2020 1:50 am
by sinus trouble
radium98 wrote: ↑Sun Aug 16, 2020 9:10 am
20191121_151256.jpgi dont find any of thoses but have a double circuit ,one have the if coil andone the quadrature i think ,because it was fitted a 22uh and ca3089 i have remove it .will try later .
Lol Radium
What is that circuit? It looks hand built but neat! Did you make it?
I have a LCR meter here and i will try to get some inductance values of the TOKOs i got from Enigma!
Re: SINUS B1 PROJECT
Posted: Wed Aug 19, 2020 2:02 am
by sinus trouble
Albert H wrote: ↑Mon Aug 17, 2020 3:07 am
This is the "front end" I used to use on Band 1. I found that it was useful to be able to vary the input amplifier gain. Sometimes, I'd use a double-tuned filter on the input, with a split capacitor as the antenna feed point - it avoided tapping the coil.
Link RX Front End.jpg
Back in the 80s, I mostly used the "Ambit" IF boards - they were cheap and gave great results, and were a bit of a time-saver. I'd build 20 of them at a time, so that I always had stock. I'd usually add an RSSI-driven relay, so that carrier presence could be used to switch the main rig. Also often I'd add a pair of NE567 tone detectors and a bit of logic, so that the main rig was started up with a tone-burst, then sustained by the RSSI. Dropping the link carrier would then shut down the main rig at the end of a broadcast. This prevented numpties from "borrowing" my rigs when they were not in use!
One thing I've missed off the scribble - there would usually be a pair of switching diodes connected between the first FET input gate and ground, to provide a measure of static protection.
Very nice circuit Albert!
A dual, dual FET Input/Mixer!
RF Head also mentioned something about a Pre amplifier stage? I was thinking over that idea but would i risk introducing extra unwanted noise in the process?
I do think the RSSI is a neat feature and has so much potential! Such a useful tool when alignment is needed!
Re: SINUS B1 PROJECT
Posted: Wed Aug 19, 2020 6:40 am
by radium98
no sinus it is not my work,a freind to me an old aged man ,who was working in 196x in an aeroport give me a scrapped receiver ,i was ineed for the ca3189 circuit so before using it ,i remove the ic and the 22uh coil,and left the toko transformer etc...my bad is i lost that circuit ,and my error is was not to dis assemble it.and it was tinned
Re: SINUS B1 PROJECT
Posted: Sun Aug 23, 2020 12:43 am
by sinus trouble
radium98 wrote: ↑Wed Aug 19, 2020 6:40 am
no sinus it is not my work,a freind to me an old aged man ,who was working in 196x in an aeroport give me a scrapped receiver ,i was ineed for the ca3189 circuit so before using it ,i remove the ic and the 22uh coil,and left the toko transformer etc...my bad is i lost that circuit ,and my error is was not to dis assemble it.and it was tinned
Well i guess we live and learn? Hopefully we can inspire the next generations as our elders did for us!
Anyways the CA3089 is literally explained with examples in the datasheet!
Technically it will demodulate any frequency you desire? Its just a case of designing the mixer and local oscillator to suit!
Re: SINUS B1 PROJECT
Posted: Sun Aug 23, 2020 4:32 am
by Albert H
The 3089 (and 3189) are wonderful chips, and are capable of lots of clever stuff. I used to do a PLL demodulator for FM using the 3189, and it would recover signals that were virtually inaudible with the usual ratio detector!
Re: SINUS B1 PROJECT
Posted: Mon Aug 24, 2020 1:23 am
by sinus trouble
Albert H wrote: ↑Sun Aug 23, 2020 4:32 am
The 3089 (and 3189) are wonderful chips, and are capable of lots of clever stuff. I used to do a PLL demodulator for FM using the 3189, and it would recover signals that were virtually inaudible with the usual ratio detector!
It is indeed a great piece of kit!
I have seen many vintage FM receivers over the years and they always fascinated me! but this is the first time i have experimented with them!
Whilst my passion is radio, Audio technology was always the root! These ICs have such a warm sound to them!
Re: SINUS B1 PROJECT
Posted: Mon Aug 24, 2020 4:42 pm
by radium98
@sinus freind this picture i do not have in my hand as a hardware ,but this from db link receiver
Looks like it uses a external local oscillator source?
I cant quite make sense of the output? Maybe it decodes some digital or stereo signals?
Re: SINUS B1 PROJECT
Posted: Tue Aug 25, 2020 3:10 am
by Albert H
That receiver has an external LO input - they used a separate PLL oscillator, to keep the digital hash away from the sensitive parts of the receiver. The output has (fairly crude) tone detection for remote switching. The ribbon cable carried power, switching signals and the audio out.
Re: SINUS B1 PROJECT
Posted: Tue Aug 25, 2020 6:42 am
by radium98
yes it use extra pll for local oscillator mixed with the selective amplifier and that you have IF than it go to thedemodulator ,wich is capable of stereo and rds signal.Note this link have no remote switching as it sais up before,andi forget the same demodulator have squelch .remember this is DB italy.old but gold,andsimple.
