ubitx LPF #bitx20help #bitx40help #ubitx #bitx40 #ubitxhelp
circular.simetry@...
Hello everybody, i have build a homebrew ubitx and i am working now on the LPF the original uses T306 toroids i have available only T376 does anybody know how many turns i have to wind?


If you use this calculator, http://toroids.info/T376.php to compare the two toroids, it shows the T376 to be about one turn more than the T306.
Joel N6ALT


Using the Schem for the uBitx you can convert nano Henry to uH using a converter (found on google) and then using the calculator on this link from Diz at kitsandparts http://toroids.info/T376.php the 1st stage for example at KA1 is 400nH=.40uH is 11.5 turns (11 or 12 will work). Hope this helps. 73 N8DAH


Woody
On 11/1/2019 19:12,
circular.simetry@... wrote:
Hello everybody, i have build a homebrew ubitx and i am working now on the LPF the original uses T306 toroids i have available only T376 does anybody know how many turns i have to wind? This might help... Go to https://toroids.info/ Enter T306 toroid and the number of turns Get the inductance Enter T376 toroid and the inductance Get the number of turns. Caveat  Due to the difference in core sizes, it might not be possible to obtain an exact inductance match. Woody, KZ4AK KZ4AK.com 


MVS Sarma
Even by using T306 , we get near by value not exact value. balance is by adjusting the turn locations etc and Farhan calls it tweaking.
On Sat, Nov 2, 2019 at 2:44 AM Woody <woody@...> wrote:


hickmodawg@...
Why not use the online calculators to get an estimate of the number of turns we need, and then use an inexpensive meter to finetune the number and arrangement of windings before installing the toroid on the board? I got a cheap LC100A meter on EBay that measures inductance and I was a little shocked to see how the inductance values of my toroids changed just from moving the windings closer or farther apart, not just from adding or subtracting winds. It seems to me, that the size and composition of the toroid, and the spacing of the windings may have an effect on the resulting inductance, not just the number of windings. I’m really still quite new to this, but, I’m wondering, why not use a meter before installing our toroids onto the board? Is it because these cheap meters are very inaccurate?


Ian Reeve
The spacing between turns,the number of turns,the wire diameter and the type of torrid all have an effect on the inductance. I use one of the "cheap" inductance meter and the readings are very close to a instrument costing nearly £100 so for me the inexpensive
one is good.
From: BITX20@groups.io <BITX20@groups.io> on behalf of hickmodawg@... <hickmodawg@...>
Sent: Saturday, November 2, 2019 8:05:28 PM To: BITX20@groups.io <BITX20@groups.io> Subject: Re: [BITX20] ubitx LPF #bitx20 #bitx20help #bitx40 #bitx40help #ubitx #ubitxhelp Why not use the online calculators to get an estimate of the number of turns we need, and then use an inexpensive meter to finetune the number and arrangement of windings before installing the toroid on the
board? I got a cheap LC100A meter on EBay that measures inductance and I was a little shocked to see how the inductance values of my toroids changed just from moving the windings closer or farther apart, not just from adding or subtracting
winds. It seems to me, that the size and composition of the toroid, and the spacing of the windings may have an effect on the resulting inductance, not just the
number of windings. I’m really still quite new to this, but, I’m wondering, why not use a meter before installing our toroids onto the board?
Is it because these cheap meters are very inaccurate?


DF1EA@...
Hello,
this tool can help http://www.dl0hst.de/dateien/software/minirk13_install.zip 73 de Chris, DF1EA


MVS Sarma
Somehow the new version is not intslling on my 64 bit win 7 laptop . Incidentally one could hombrew vk3bhr lc meter 2 using pic16f628a. It works well, i have been using it for a decade now. Sarma vu3zmv
On Sun, 3 Nov 2019, 2:18 am , <DF1EA@...> wrote: Hello,

