IDX-PRO+VDI

[Thomas]

What you saw was the copper area, should be .16mm

[dfbowers]

Hi Barry. I found that the Tx wire size mattered more than Rx.. if Tx is too small you do not get full tx amplitude. If too large it becomes difficult to work with. I built two concentrics for the Idx with different wire sizes for the rx and could not tell any difference except the value of R was a little off. Hope you are staying cool down there in aussie land! Its plenty cold up here!
Don..

[hoadlies]

THANKyou THOMAS for that information ..

Nice calculator ..

CHEERS BARRY..

[hoadlies]

Hi Barry. I found that the Tx wire size mattered more than Rx.. if Tx is too small you do not get full tx amplitude. If too large it becomes difficult to work with. I built two concentrics for the Idx with different wire sizes for the rx and could not tell any difference except the value of R was a little off. Hope you are staying cool down there in aussie land! Its plenty cold up here!
Don..

HI DON thanks for the Reply ,, YES its B*****y hot here mate 44c for 4 day in a row ,I will send some of over to you HA.Haaar..

OK I am doing a DD coil [1st attempt] I used 0.7 wire for TX it ended up OK as to resistance reading & mH come out ok [Did the test as Silver-Dollar described with the S/GEN & my old single scope & 1 uf cap seems around the camp 6.5-6.6 Khz..
But for RX coil still unfinished I wound 290 Turns of 0.24mm wire as I had it here to use for TGSL now not doing that so used it for IDX DD.., I am yet to tighten up coil for a test mH reading !!]
But as it is Its close to the readings You describe for RX ..I will report back after More work on it ..

Can I do a similar test for RX as I did with the TX using the Signal Gen & scope & cap trials ,If so what frequency am I looking to obtain?????DID I read 4900hz ?????ie 4.9 khz????

SHOULD be a cool change coming tonight ?? this will allow me to get out to my W/shop where I am working on these coils ..Still awaiting my KIT for IDX ,Very keen to get started on my 1st build ..I have printed all I can find on the various build mods etc posted here BY EDUARDO ..

I am to use aluminium foil [Self stick on a roll] I cannot find Graphite dry-lube as yet But my son gave me a can of MOLY-cote spray Dry-Lube """MOLYDNIUM ????? I will test that on paper to check conductance ???Any one used that ????

THANKS for the Help Much appreciated ''VINTAGE-BARRY'' @74..

[Silver Dollar]

Thicker TX wire changes the "Q" in a good way. The lesser resistance helps with creating a stronger field.

On RX the thinner wire is actually better as the increased resistance matches impedance better for
less noise. Of course these are just guidelines for making the best you can. I used 0.25 mm wire for
both coils on my TGSL (but found out the wire was more like 0.22 mm) but since reading about
IGSL have made a 0.55 mm TX coil and a real 0.25 mm RX with lots more windings.

The trick is that no matter what you do some coils come out better than others so build one and glue
it but be prepared to throw it away if it doesn't work well. I think Ivonic tossed 1 out of 4. The difference
between a good one and bad one is depth and or noise.

On shielding I am currently making center tapped coils with no shield for best performance. My second choice
would be some sort of screening (like you use on the windows to keep bugs out). I found some that you can
solder to (a loose shield or broken ground to the shield will make your coil unusable). Aluminium foil works but
thinner is better. I tried some Mylar balloon type foil but it rips easy and is hard to work with. Graphite is a good
choice, I'm not sure about moly, although it is a metal I've never heard of how well it conducts...

[Valters]

Now one beginner question.
In my first IDX I use MKT +/-10% type capacitors, now I will try second one.
Is sense to use FKP +/-2,5% (3x time expensive that 5% and 10x than 10%) type capacitors or it is enougt with +/-5% MPF type capacitors or even 10% MKT?

Your opinion?

[dfbowers]

HI DON thanks for the Reply ,, YES its B*****y hot here mate 44c for 4 day in a row ,I will send some of over to you HA.Haaar..

OK I am doing a DD coil [1st attempt] I used 0.7 wire for TX it ended up OK as to resistance reading & mH come out ok [Did the test as Silver-Dollar described with the S/GEN & my old single scope & 1 uf cap seems around the camp 6.5-6.6 Khz..
But for RX coil still unfinished I wound 290 Turns of 0.24mm wire as I had it here to use for TGSL now not doing that so used it for IDX DD.., I am yet to tighten up coil for a test mH reading !!]
But as it is Its close to the readings You describe for RX ..I will report back after More work on it ..

Can I do a similar test for RX as I did with the TX using the Signal Gen & scope & cap trials ,If so what frequency am I looking to obtain?????DID I read 4900hz ?????ie 4.9 khz????

SHOULD be a cool change coming tonight ?? this will allow me to get out to my W/shop where I am working on these coils ..Still awaiting my KIT for IDX ,Very keen to get started on my 1st build ..I have printed all I can find on the various build mods etc posted here BY EDUARDO ..

I am to use aluminium foil [Self stick on a roll] I cannot find Graphite dry-lube as yet But my son gave me a can of MOLY-cote spray Dry-Lube """MOLYDNIUM ????? I will test that on paper to check conductance ???Any one used that ????

THANKS for the Help Much appreciated ''VINTAGE-BARRY'' @74..

Hey Barry.
When I built my IDX coils I copied what I could measure from my 6" Blue Max coil. The phasing on my home builts came out good..meaning the GB and DISC pots were somewhat mid-range. The phasing is most critical as you will not be able to GB is this is off. Even 1/2 a turn off with the Tx coil can screw things up. The IDX coils are less tolerant than the TGSL coils when it comes to this. You may want to wait until you complete your PCB before you cast your coils in glue as you may need to make a few minor tweeks but this should land you in the ballbark.
Don

[golfnut]

Valters... Going for tight tolerance expensive caps will not help you .

Barry, the molybdenum is not used for a couple of reasons - 1) Its magnetic! Not what you want 2) a great friction modifier - the coil and potting may drop out

S

[hoadlies]

Thicker TX wire changes the "Q" in a good way. The lesser resistance helps with creating a stronger field.

On RX the thinner wire is actually better as the increased resistance matches impedance better for
less noise. Of course these are just guidelines for making the best you can. I used 0.25 mm wire for
both coils on my TGSL (but found out the wire was more like 0.22 mm) but since reading about
IGSL have made a 0.55 mm TX coil and a real 0.25 mm RX with lots more windings.

The trick is that no matter what you do some coils come out better than others so build one and glue
it but be prepared to throw it away if it doesn't work well. I think Ivonic tossed 1 out of 4. The difference
between a good one and bad one is depth and or noise.

On shielding I am currently making center tapped coils with no shield for best performance. My second choice
would be some sort of screening (like you use on the windows to keep bugs out). I found some that you can
solder to (a loose shield or broken ground to the shield will make your coil unusable). Aluminium foil works but
thinner is better. I tried some Mylar balloon type foil but it rips easy and is hard to work with. Graphite is a good
choice, I'm not sure about moly, although it is a metal I've never heard of how well it conducts...

HI ,,S/D ,, THANKS for the Input it is good info from you ,,that have built many coils ,,I will no dought have to build a few coils to get it Right ,But learn along the way ..

Interesting Fly-Screen YES you can get Brass Flyscreen I think & can solder that Ok ..
IT seems the GRAPHITE Spray is the Simplest method seen here on the site & or to mix powdered Graphite with a glue -Varnish etc ..

I tried the MOLY-COTE spray & its ''NOT'' conductive so thats squashed that rout..

INTERESTING the Centre-tapped Coils ,Would they be difficult to build as to obtaining the centre tap ??? ,Or do you wind 2x coils so as to adjust each to balance????
I guess if you were positive of No of turns & tapped at the Middle of winding as you wound it ????

IT seems that we need A good supply of various guages of wire [NOT CHEAP] here in OZ at least .
I read somewhere that Old TV tubes had some usable wire behind them & I have just thown out several older models As Digital has now taken over here in OZ ,I also thew-out many old style Comp,
Monitors [BUGGA] Need to scrounge some-up HA.Haar..


I can buy rolls of 0.2 @ $22.00 AUD But it will only do one RX coil ??,, I am still looking for a better place to buy larger rolls cheaper ..


THE TX Coil I wound was Wire from a 12v oil-filled coil [CAR-IGN] primary easy to reclaim & was 0.7 , THERES Just enough for the 35 turns with some over ...& using YOUR explained method of the SIG-GEN & SCOPE worked out great ''THANKS''..

I much appreciate all the Help I have been given BY you S/D, G/nut,DON & others I hope I can complete this IDX to Show I have not Wasted your Time ..

WELL we got a change here today & I can get off my ''Backside '' & get out to my W/Shop as its been too hot during the day to work in there 44c ..

CHEERS TO ALL,,,,,,,,,BARRY..

[hoadlies]

Hey Barry.
When I built my IDX coils I copied what I could measure from my 6" Blue Max coil. The phasing on my home builts came out good..meaning the GB and DISC pots were somewhat mid-range. The phasing is most critical as you will not be able to GB is this is off. Even 1/2 a turn off with the Tx coil can screw things up. The IDX coils are less tolerant than the TGSL coils when it comes to this. You may want to wait until you complete your PCB before you cast your coils in glue as you may need to make a few minor tweeks but this should land you in the ballbark.
Don

HI DON THANKS for you valued input YES I really need to wait untill I get my Kit & get it running prior to fixing the Coils ..
Wire Diam & No of turn to achieve the correct balance seem's most important ..


I will after this DD coil build have a go at your Coplaner Coil you described ,But I need to Stock-up on some Wire & build some winding formers to suit & obtain some of the Graphite spray you use ..
I will persevere,,Mate..

I thankyou for the Input ,,,,,,,,,,CHEERS BARRY..

[hoadlies]

Valters... Going for tight tolerance expensive caps will not help you .

Barry, the molybdenum is not used for a couple of reasons - 1) Its magnetic! Not what you want 2) a great friction modifier - the coil and potting may drop out

S

YES G/NUT,, I tried some on some paper & found also that it is not conductive either ,, I need to mix some Graphite powder as I do have some i will experiment with that ..

HAVE a Good-Day..MATE,,,,,,,,,,BARRY..

[golfnut]

graphite - I do square test cards, I struggled to get repeatability. I get patches or zones of good low res. Then areas that are high.

Can be tricky, commercial coil vendors all do their graphite or carbon a bit differently and guard it.

You want a few k ohms per square

The ratio of paint, epoxy, carrier to graphite I got best results with was 50/50 by mass, my better ones were with really thin epoxy- as thin allows the graphite to touch together, all were a bit average, I don't have a killer recipe...

Satdave got results with cheap yacht varnish and graphite.

Sand paper the shell to key it.

Carbon paint for remote control traces would be good - this is a high temp industrial process and no use for us. There is a low temp carbon but sourcing as a amateur is tedious.

Graphene is something that should be great - but too new and pricey

The best function for time outlay is cheap survival blanket, it must have exposed metallisation on one surface so fine drain wire connects - some from value shops are often best. Premium ones from adventure stores have plastic both sides with the metal inside - you cant connect to these.

[Silver Dollar]

Part of the trick to using Graphite is to burnish (or rub) the surface after it dries. This spreads the
molecules and makes them contact for a continuous connection...

[golfnut]

good tip, maybe try that. Im sure mr ML et al don't - but for a one off

[Koala]

Your opinion?

All IC's are not the same.

RS and Farnell give specs for each manufacture. Originally I was going to go for the cheapest but in the end I bought the best.

Some from country's that IC"s are difficult to buy seem to have only 75% the distance even though they have built different types of MD. Could this be making the difference. Has anyone tried worst case against best.