Adding IR to an old receiver (STR-G3), need help...

[Knight]

Hi!

I would like to add IR control to an old receiver I have here...

The receiver in question is a Sony STR-G3 which used to be controlled by some sort of "mouse" (RM-VP1) which is unfortunatly broken...

[That amp was what was called at the time a "Visiontouch" receiver...]

There is a way to add IR control to that amp using a hack described at the following URL: http://web2.airmail.net/will/str0g3.html

I am not (yet) very good with a soldering iron but I think I can do it, the problem I have is finding the right parts...

I know the general principle behind caps & resistors (and definitly enough to know that I need more info on the caps & resistor they suggest be used).

- The IR receiver they ask for (Radio Shack 276-137), I got one with what seems to be the same pinout and with almost the same part number 276-137a so I'm pretty sure I've got a compatible part.

- The resistor is described as an approx 1k Ohm Resistor but there's no mention about wattage or tolerance...

The cap is described as an 1uF Capacitor. From the look of it it's an electrolytic one, but there no mention of voltage or any other spec about it I should be looking for...

I found the service manual for that amp at the following URL http://www.eserviceinfo.com/download...ny_STR-G3.html but since that part wasn't installed at the factory it looks like it wasn't included in the schematics either...

Can anybody please tell me what part I should get and where could I order them (from Canada).

Thank you and have a nice day!

Nick

PS: I did try to contact the person that publish that fix but never got any answer ...

[arneson]

Re: Adding IR to an old receiver (STR-G3), need help...

This should be a simple mod.
Cap is most likely 10 microfared, 6.3 volt.
Specs on these parts are totally loose.
If I were to do this I would be using all parts from some useless unit, like a sat tv reciever.
One of the most usefull features of Sonys for me is the RF remote because I must hide the units under bunks and in the gally and such, but they allow either or both IR/RF.

[gonzo0815]

Re: Adding IR to an old receiver (STR-G3), need help...

As Arneson already said, you can use any cap with 1uf to 10uf and at least 6,3v (more won`t hurt, but input voltage is 5 v). this cap is only to stabilise the power for the reciver IC, which is in fact a complete IR reciver & prozessor to decode the signal. The resistor is to put the data line high (pull up), the reciver will do have a negativ output logic, it will sink the small curent from the resistor and the line will go low if a digital high is meant. So there isn`t mucht current. to handel (about 5mA@1k leeding to a total of 0,025w power.). So any size will be ok. If you want to understand the circuit, google for the datsheet of this receiver and you will se how simple it is and there are normaly some values printed in.

[Knight]

Re: Adding IR to an old receiver (STR-G3), need help...

Hi!

This should be a simple mod.
Cap is most likely 10 microfared, 6.3 volt.
Specs on these parts are totally loose.
If I were to do this I would be using all parts from some useless unit, like a sat tv reciever.

I think in my case I'll try to get new parts because I think I would have more difficulties soldering something on which the leads are already cut and I don't have that many spare parts...

One of the most usefull features of Sonys for me is the RF remote because I must hide the units under bunks and in the gally and such, but they allow either or both IR/RF.

That "mouse" uses RF but as it actually move a cursor on the screen you must actually see where the cursor is on the screen...

Thank you very much for your help!!

Nick

[Knight]

Re: Adding IR to an old receiver (STR-G3), need help...

Hi!

As Arneson already said, you can use any cap with 1uf to 10uf and at least 6,3v (more won`t hurt, but input voltage is 5 v).

I had noticed (there are some specs on the package it came in) that the receiver was a 5V device but as I didn't know what the other parts were used for so I wasn't sure if there was a higher voltage going through them or not...

this cap is only to stabilise the power for the reciver IC, which is in fact a complete IR reciver & prozessor to decode the signal.

At your suggestion I started looking for a datasheet and found the one of the original receiver (276-137) and a few other compatible (or almost compatible, some of them change the pinout) and a few circuits based on that receiver...

I was very surprised to see that something which look like a LED and a transistor put together (mine is in the metal casing like the one that was used on the website but the compatible parts looks like that) was actually that powerful... With very few parts they connected the receiver directly to the serial port of a PC (this receiver and compatible/simlar devices are used a lot for the LIRC IR receivers).

The resistor is to put the data line high (pull up), the reciver will do have a negativ output logic, it will sink the small curent from the resistor and the line will go low if a digital high is meant. So there isn`t mucht current. to handel (about 5mA@1k leeding to a total of 0,025w power.). So any size will be ok. If you want to understand the circuit, google for the datsheet of this receiver and you will se how simple it is and there are normaly some values printed in.

I cannot claim I understand entirely how it works but I do have a better idea of how it works now...

So if I understand what you said correctly, as far as the resistor is concerned, any 1K resistor (or close to that is ok) and I probably don't even have to bother with the tolerance and wattage.

For the cap, it must be around 1uF to 10uF, 6.3V or above. It loks like it's electrolytic so I'll have to make sure I respect the polarity... Is there anything else I must ask/look for (low esr? etc...)?

BTW, it looks like the receiver I have works at 38Khz while the one that was described in the fix worked at 40Khz... From reading on the web it looks like most remotes actually work at close to 38Khz and both parts should work for these remotes and it might even work better with a 38Khz part (better range)... Did I understand that correctly or should I start looking for a 40Khz part?

As for a place to obtain them, I saw a seller on Ebay which has a very good feedback and sells Nichicon (I hope they are not fakes...)... Would you trust an Ebay seller for these kind of parts?

Thank you very much for your help, it is and was much appreciated!!

Have a nice day & weekend!

Nick

[gonzo0815]

Re: Adding IR to an old receiver (STR-G3), need help...

The capazitor could be a generall purpose type, no specially low esr or something else is required. In any way, i would take a 63v 105°C rated one, as in generall their lifetime is mutch longer. For the reciver i think even at ebay this shouldn`t be a problem. Regarding capacitors it depends of the source from wich the ebayer will source those caps and if he is knowledgeable enough to tell the differenc between the counterfaith and the real thing. I have sourced many things from ebay and all are reliable and honest upt to now.
I have build some of those IR reciver for pc systems, and it was pretty easy(exept the software setup of those variouse programms...). Both types should work, as long as the damping filter isn`t that narrow. In doubth look at the datasheet, may be they state the sensitivity for both frequencies.

[Knight]

Re: Adding IR to an old receiver (STR-G3), need help...

Hi!

The capazitor could be a generall purpose type, no specially low esr or something else is required.

O.k.

In any way, i would take a 63v 105°C rated one, as in generall their lifetime is mutch longer.

Higher temperature and higher voltage?

Regarding capacitors it depends of the source from wich the ebayer will source those caps and if he is knowledgeable enough to tell the differenc between the counterfaith and the real thing.

One can always hope that since they sell electronic parts they are knowledgeable enough to be able to identify counterfeit parts (though that must not be always easy...)

I have sourced many things from ebay and all are reliable and honest upt to now.

I bought quite a few things on Ebay and this has overall been a positive experience with a few exceptions...

[But what I bought had very few chances of being counterfeit...]

I have build some of those IR reciver for pc systems, and it was pretty easy(exept the software setup of those variouse programms...).

I have an Usb-Uirt but I might try later to build one of these receivers just for the fun of it...

Both types should work, as long as the damping filter isn`t that narrow. In doubth look at the datasheet, may be they state the sensitivity for both frequencies.

The part I've got (Radio Shack 276-137a) has a "bandpass center freq(uency)" of 38Khz and (but I'm not sure if it is the right spec) a "-3dB band with at 38Khz"*** of 3Khz which I assume means that it can receive from 36.5Khz to 39.5Khz.

The original part (Radio Shack 276-137) has a "bandpass center freq(uency)" of 40Khz and a "-3dB band with at 38Khz"*** of 4Khz which I assume means that it can receive from 38Khz to 42Khz.

It sounds like my part should be ok as long as the carrier frequency of the remote is closer to 38Khz than 40Khz..

Oops, it looks like I have to go otherwise I'll arrive late at work...

Thank you very much for your help!!

Have a nice day!

Nick

[gonzo0815]

Re: Adding IR to an old receiver (STR-G3), need help...

Higher temperature and higher voltage?

Only a suggestion, you can use anthing other and it will last probably very long too.
It is safe to use higher voltage rated caps, usually i chose about 20v above the operating voltage. Only low esr caps are used with very low tolerance (e.g 6,3v @5v rail).
And for that small vallues size isn`t that important. The higher the voltage the bigger are those caps usually and bigger caps will last longer as a rule of thumb.
Same with the 105°c rating, this means that this device will have a longer life under normal condition, as they have more elektrolyt or are altered in an other way to reduce loss of elektrolyt and witstand the heat. Think about an higher overall quality of 105°C devices, and those few cents are worth it.
And additionally 63v is a very common voltage and is easily availiable.
But a mutch lower voltage will work too, if space is a consideration.
This all is for generall purpose caps, if you could obtain a seciall long life series cap from on of the well known manufacturer (e.g ZLH or something with 10000h lifetime), it is no problem taking this (but this could be seriouse overkill on that aplication).

One can always hope that since they sell electronic parts they are knowledgeable enough to be able to identify counterfeit parts (though that must not be always easy...)

Nick

well, in germany most supplier won`t even know what low esr is, and in most cases they not even state the manufacturer....so i don`t know where you buy your stuff, but wouldn`t that sure that they are even aware of those problems.

The part I've got (Radio Shack 276-137a) has a "bandpass center freq(uency)" of 38Khz and (but I'm not sure if it is the right spec) a "-3dB band with at 38Khz"*** of 3Khz which I assume means that it can receive from 36.5Khz to 39.5Khz.

The original part (Radio Shack 276-137) has a "bandpass center freq(uency)" of 40Khz and a "-3dB band with at 38Khz"*** of 4Khz which I assume means that it can receive from 38Khz to 42Khz.

It sounds like my part should be ok as long as the carrier frequency of the remote is closer to 38Khz than 40Khz..

Nick

Well, i think you are right, i am not shure, but as far as i remember i think both devices have enbough bandwidht to receive both frequenzies, sacrifying the usuable distanc a little.

[Knight]

Re: Adding IR to an old receiver (STR-G3), need help...

Hi!

Only a suggestion, you can use anthing other and it will last probably very long too.

I'm very open to these suggestions, I just wanted to make sure you meant 63V and not 6.3V...

It is safe to use higher voltage rated caps, usually i chose about 20v above the operating voltage. Only low esr caps are used with very low tolerance (e.g 6,3v @5v rail).
And for that small vallues size isn`t that important. The higher the voltage the bigger are those caps usually and bigger caps will last longer as a rule of thumb.

O.k.

Same with the 105°c rating, this means that this device will have a longer life under normal condition, as they have more elektrolyt or are altered in an other way to reduce loss of elektrolyt and witstand the heat. Think about an higher overall quality of 105°C devices, and those few cents are worth it.
And additionally 63v is a very common voltage and is easily availiable.

But a mutch lower voltage will work too, if space is a consideration.

From the pics it looks like I will have to put the caps on its side, would a 63V cap be too big for that?

This all is for generall purpose caps, if you could obtain a seciall long life series cap from on of the well known manufacturer (e.g ZLH or something with 10000h lifetime), it is no problem taking this (but this could be seriouse overkill on that aplication).

And other parts of the receiver would probably go bad before that...

well, in germany most supplier won`t even know what low esr is, and in most cases they not even state the manufacturer....so i don`t know where you buy your stuff, but wouldn`t that sure that they are even aware of those problems.

I'm surprised it seems to be so difficult in Europe to get parts... I'm not sure if we can still buy them but many years ago many of the electronics magazines we could buy here (Canada) came from Europe...

My problem as far as getting parts is finding a place where it won't cost me an arm and a leg to purchase only two parts (cap & resistor). Ebay would be the best because I can order in small quantities otherwise it looks like I could order from Digikey or Newark if I find other things to order..

I've recently ordered kits from Qkits (so I can practice myself to improve my soldering skills) but they unfortunatly only sell kits, not parts...

Well, i think you are right, i am not shure, but as far as i remember i think both devices have enbough bandwidht to receive both frequenzies, sacrifying the usuable distanc a little.

If worst come to worst I could unsolder the 38Khz and look for a 40Khz part if it doesn't work... I tried searching on the web to see if I can find out at which frequency Sony remotes usually work and I haven't found a definitive answer yet...

Once again thank you very much for your help!!

Have a nice day!

Nick

[arneson]

Re: Adding IR to an old receiver (STR-G3), need help...

I'm surprised it would be hard to find what you need.
Many devices on the street have this circuit, I even have a tub spa with IR unit.
The cap is the easiest, it's the most common cap ever made, 10microfarad, 6.3 volt...
The resistor, also not special, getting a universal controler to trigger the response you want? could be tricky.

[Knight]

Re: Adding IR to an old receiver (STR-G3), need help...

Hi!

I'm surprised it would be hard to find what you need.
Many devices on the street have this circuit, I even have a tub spa with IR unit.
The cap is the easiest, it's the most common cap ever made, 10microfarad, 6.3 volt...

The only used spare parts I have now are the one that were damaged by lightning, somehow I don't think I should use these...

[I am a programmer/network admin that wish he was better with a soldering iron and still has a lot to learn... I don't have spare parts lying around everywhere ...]

I also need a cap with pretty long leads if I am to put it on its side like it was done on the fix I found on the web...

The resistor, also not special,

The resistor I agree is a lot easier to find... I don't even have to wonder about brands or anything... Any resistor as long as it's not SMT should work...

getting a universal controler to trigger the response you want? could be tricky.

According to the fix I found on the web, it responds to normal Sony codes... If needs be I could also reprogram one of my One-for-All (or compatible) remotes with my JP1 cable...

Thank you and have a nice day!

Nick

PS: I think Newark has tips for my soldering iron (Weller) that I could buy at the same time so if I can order from them (hope they don't require a company account) I might end up ordering from them...

[gonzo0815]

Re: Adding IR to an old receiver (STR-G3), need help...

Well it isn`t that hard to get ektronic parts here in Germany, but only the usuall stuff (for the usuall experiemter). There anren`t mutch people who recap IT stuff and there are not mutch IT stuff produced there. So any speciall components like low or ultra low esr caps aren`t availiable in those radio shake like stores. But of course, for producktion quantitiy there isn`t any problem sourcing all what is being deshired....and for professionallsthere are a lot of speciallized suppliers for usuall repair parts. But not for end users...
Some of the bigger elektronic stores sell even those very bad low esr caps like Lelon and others listed here as very ugly choice. Yet they don`t know the difference.
And farnell etc. are far to expensive as most low esr caps are only in the USA stock, adding 20€ per order....
But of course, sourcing those reciver parts was no problem, as even small shops have this in stock.

[Knight]

Re: Adding IR to an old receiver (STR-G3), need help...

Hi!

Sorry for the delayed reply...

Well it isn`t that hard to get ektronic parts here in Germany, but only the usuall stuff (for the usuall experiemter). There anren`t mutch people who recap IT stuff and there are not mutch IT stuff produced there. So any speciall components like low or ultra low esr caps aren`t availiable in those radio shake like stores. But of course, for producktion quantitiy there isn`t any problem sourcing all what is being deshired....and for professionallsthere are a lot of speciallized suppliers for usuall repair parts. But not for end users...

From your description it looks like it's easier to get the normal stuff than here (Canada)... I went to two stores that used to be "Radio Shack"s here (they were replaced by "The Source by Circuit City", FYI that's their name include the "by Circuit City" part...) and one of them only had a couples of switches, plugs and leds...

I was more lucky at the other but I couldn't find a part that had the specs you suggested so I'll probably end up buying it from Digikey or Newark...

Some of the bigger elektronic stores sell even those very bad low esr caps like Lelon and others listed here as very ugly choice. Yet they don`t know the difference.
And farnell etc. are far to expensive as most low esr caps are only in the USA stock, adding 20€ per order....
But of course, sourcing those reciver parts was no problem, as even small shops have this in stock.

Count youself lucky, you do have more choice than I have here...

BTW, at one of those "The Source" store they sold a package that had 20 caps apparently chosen at random (no two package appear to be the same)... In one of them I could see Rubycons and Nichicons in the same package as Lelons (as you mentionned they do not seem to know there a difference)...

As soon as I get the parts I'll try the fix and I'll let you know what happened...

BTW, I almost got my hands on one of the original remotes for my receiver (mine is broken) on Ebay but a #@#(@! over bid me in the last 10 seconds (probably done using one of those sites that let you bid at the last minute... )

Thank you very much and have a nice day!!

Nick

[gonzo0815]

Re: Adding IR to an old receiver (STR-G3), need help...

Well, if your remot is only elektrically broken, may be it is fixable. In my experiences in rmotes the most sensitive component is the 455khz resonator. It is a quarz crystall, wich will breake if the remot is falling down. It is in most cases located in a recktangular case, often yellow or red with a 455 marked.
If it is brocken, you often will hear some noise when shaken the remote, like there are some parts loose.
Bad solderjoints are very comon too. And the usuall carbon key pads aren`t that durable, but may be some cleaning or some conductive repair coating could do the trick.
Otherwiese it is possible to get a new remote from a repair stuff seller, at least in Germany there are some services wich will carry some remotes and a database to lock which is needed for the specific device. So may be in Germany i could manage to get such an remot. Duno wich it will cost shiped to Canada, but probably expensive.

[Knight]

Re: Adding IR to an old receiver (STR-G3), need help...

Hi!

Well, if your remot is only elektrically broken, may be it is fixable.

I was able to make it work by cleaning the contacts as much as I could (I'm not sure how the thing is put together but I can't seem to be able to get the circuit board out of the remote's casing)...

Unfortunatly, that was not the sole problem with the remote, the battery door is broken and I've been unable to find a way to make it hold properly...

And the usuall carbon key pads aren`t that durable, but may be some cleaning or some conductive repair coating could do the trick.

Cleaning it really seems to have done the trick (at least as far as making it work again)...

FYI, if you were wondering what the remote actually looks like, I found the following picture on the net:

http://www.dvdremotecontrols.com/Mfr...dio/RM-VP1.jpg

Otherwiese it is possible to get a new remote from a repair stuff seller, at least in Germany there are some services wich will carry some remotes and a database to lock which is needed for the specific device. So may be in Germany i could manage to get such an remot. Duno wich it will cost shiped to Canada, but probably expensive.

I did found a place where they sold one but it was more than 300 Euros, a lot more than that receiver is worth now...

[It still is quite useful but it's quite an old receiver...]

Thanks for the offer though...

BTW, I did have things shipped from Europe in the past (from Ebay sellers mostly) and it wasn't that bad as far as S&H costs but they were relativly small...

Thank you very much and have a nice day!!

Nick