TESORO GOLDEN SABRE

[eduardo1979]

tgsl

tgsl Jpeg

[eduardo1979]

tgsl

tgsl ok

[eduardo1979]

tgsl

tgsl circuit ok

[eduardo1979]

Tgsl

Tgsl capacitor error.

[dfbowers]

Interesting - resembles Vladimir's slower response version, which I think makes a lot of sense. I plan to make one with very similar values. The audio circuit is a wild card, still lots of questions and myths surrounding that. I like layouts that put the speaker ground close to the power supply ground and negative supply circuit -- all the high current stuff together.

It seems like most of the changes are in the left half of the schema, but your pics are of the right half... any reason?

Sadly still not finding any time to tinker but want to badly...

Keep up the good work...

-SB

I was only considering the general layout and parts differences. The schematic would be the same for the left half with the exception of a few component values, but I admit, the changes could make significant differences. I will let you know in a day or so as I will probably put it together tonight..

If I have time and get a .pdf plug in to edit the schematic I can document this version.

I think Silverdog could benefit from having matching schematics with his boards.

[simonbaker]

Updated.. Sorry.. Error in previous post.

Don

Interesting - resembles Vladimir's slower response version, which I think makes a lot of sense. I plan to make one with very similar values. The audio circuit is a wild card, still lots of questions and myths surrounding that. I like layouts that put the speaker ground close to the power supply ground and negative supply circuit -- all the high current stuff together.

It seems like most of the changes are in the left half of the schema, but your pics are of the right half... any reason?

Sadly still not finding any time to tinker but want to badly...

Keep up the good work...

-SB

[dfbowers]

Updated.. Sorry.. Error in previous post.

Don

[dfbowers]

Hi, has anyone posted up the black and white schematic for Eduardo's version of the TGSL? I took delivery of the PCB from Siverdog.. Nice! Just looking at it quicky, provisions for some of the decoupling caps have been deleted, the gain has been doubled around U103? and the final audio is circuit is different.

It's self documenting but wanted to look at things from another perspective..

Maybe the missing decoupling caps would be OK if TLO71's were substituted for the LM308s? Or.. maybe I can kludge them in..

I'll put it together and do a comparison with Ivconics, but I wanted to see what else is different and work up a change in the parts list.

Thanks

Don

Traced the PCB out. The only significant differences are below.

The only other things I see:

C14 and C17 are doubled - to 10uF.
R29 and R31 increased from 470k to 1m.
LM7808 decoupling removed.
CD4024 decoupling removed.
100uF decoupling added to U103.

Has anyone else built this from Silverdogs PCB yet?

Eduardos is on the left.

Don

[dfbowers]

Here is a PDF of the layout.

eduardo1979: what layout did you base your layout on?

Can you post the exact schematic for the layout?

Cheers,

-SB

Hi, has anyone posted up the black and white schematic for Eduardo's version of the TGSL? I took delivery of the PCB from Siverdog.. Nice! Just looking at it quicky, provisions for some of the decoupling caps have been deleted, the gain has been doubled around U103? and the final audio is circuit is different.

It's self documenting but wanted to look at things from another perspective..

Maybe the missing decoupling caps would be OK if TLO71's were substituted for the LM308s? Or.. maybe I can kludge them in..

I'll put it together and do a comparison with Ivconics, but I wanted to see what else is different and work up a change in the parts list.

Thanks

Don

[simonbaker]

I don't want to step on anybody's toes, but I think somebody is splitting hairs.

"Making coil for TGSL" suggests 25mm copper. According to my wire data reference, that is equivalent to something between 30AWG~30.5AWG.

Manurespreder wants to use what reads like a 29.5AWG equivalent. Can that really be a big problem?

Adding two turns to each coil should just about compensate inductance, and I think the reduced RX coil resistance (less by about 7 ohms) will cause less than 1 degree phase shift difference. No Big Deal.

Manurespreder did not say exactly what his copper thickness is, so this diatribe is based on an estimate based on incomplete data.

My wire data reference is from Allem.com

http://www.allem.com/files/magwiredim.pdf

My wire thickness differences were a little bigger than that, so in my case it was resistance was about 7 ohms vs. 20 ohms, a very significant difference in Q.

However, you assume his circuit is tuned correctly -- if not, even a 50% resistance difference could cause some problem phase shift if TX freq and RX resonant freq are closer than they should be.

But I wouldn't let .3 mm wire stop me! Make the coils, let's see how they work!

-SB

[Qiaozhi]

I don't want to step on anybody's toes, but I think somebody is splitting hairs.

"Making coil for TGSL" suggests 25mm copper. According to my wire data reference, that is equivalent to something between 30AWG~30.5AWG.

Manurespreder wants to use what reads like a 29.5AWG equivalent. Can that really be a big problem?

Adding two turns to each coil should just about compensate inductance, and I think the reduced RX coil resistance (less by about 7 ohms) will cause less than 1 degree phase shift difference. No Big Deal.

Manurespreder did not say exactly what his copper thickness is, so this diatribe is based on an estimate based on incomplete data.

My wire data reference is from Allem.com

http://www.allem.com/files/magwiredim.pdf

I assume you meant to say 0.25mm copper.
Yes - I agree. The difference in coil resistance will have a negligible effect.

[porkluvr]

I don't want to step on anybody's toes, but I think somebody is splitting hairs.

"Making coil for TGSL" suggests 25mm copper. According to my wire data reference, that is equivalent to something between 30AWG~30.5AWG.

Manurespreder wants to use what reads like a 29.5AWG equivalent. Can that really be a big problem?

Adding two turns to each coil should just about compensate inductance, and I think the reduced RX coil resistance (less by about 7 ohms) will cause less than 1 degree phase shift difference. No Big Deal.

Manurespreder did not say exactly what his copper thickness is, so this diatribe is based on an estimate based on incomplete data.

My wire data reference is from Allem.com

http://www.allem.com/files/magwiredim.pdf

[simonbaker]

Using .3mm will change your inductance as well as resistance. The reason being is that more wire will be added to your coil in order to achieve the same number of turns. Your mean radius will increase as well as your outside diameter. Also, coil weight thickness will increase..

I have no doubt that you can get it to work with .3mm wire but you cannot use the guidelines in the .pdf and expect the same results.

I bought a roll of "BAE wire AWG 30 SPN RED MW80c/155C" off of e-bay cheap.. almost a lifetime supply..

I tried to make some RX coils with thick wire like that and had much trouble.

I'm not sure but I think the problem is that because the resistance is lower, it makes the Q of the resonant circuit much higher and changes the phase shift/frequency relationship which can throw off your discriminator unless you are very careful. It also magnifies the noise pickup at resonance (although it reduces it at off-resonance). But the TX signal is off-resonance, so it may be actually causing a type of signal-to-noise problem.

I tried experiments where I added a resistor to the RX coil to try to make it act like thinner wire. For some reason I did not have noticeable improvement, but in theory, that is a technique that may help. (Because I was experimenting with prototype circuits, I probably had poor depth for many other reasons too.)

All I know is I have not yet had good success with thick wire. However, I feel that with very careful design, it should be possible, and that using thick wire for the TX coil should actually be better potentially.

If it is the only wire you have available, I would go ahead and try it. And try putting a 15 ohm resistor in series with the RX coil. (It may also work to put a higher resistance resistor in parallel with the RX coil, but you need to calculate it to get the same Q.)

Regards,

-SB

[dfbowers]

That's not as bad as I would have thought. So going from .25mm to .3mm gives a difference of about .2mH. Adding sheilds always changes things as well. It can add up to 400pF to the total C depending on how well the wires are insulated. If that's all you have, I might be tempted to try .3mm wire. Just add about 5 turns more to the Rx coil.

Anyone else have any thoughts??

[Qiaozhi]

Ouuuh thank you. I am living in a crappy country called Lithuania so buying from ebay isn't very cheap cause delivery prices are hight.

Local assortment of parts are very bad and everything has high price how example LM309 costs 10$ each! on ebay I bought 10 for 12$ ...

And to buy Cu 0.27 is like impossible I can order only 0.3 and I have to wait a half of month to arrive..

Here's the sort of difference you can expect between 0.27 mm and 0.3 mm.