From: "Clemens Paul" <cpaul@gmx.net>
To: <rsgb_lf_group@blacksheep.org>
References: <08B5A81DD2D14C84874DD10EEB145569@lindavideo> <4DC3B18B20A94764A9ADCC2B5453447A@Clemens0811> <EEE5520AEAD742A9AA7DE4C0EE2A223E@lindavideo>
In-Reply-To: <EEE5520AEAD742A9AA7DE4C0EE2A223E@lindavideo>
Date: Sat, 17 Oct 2015 22:03:27 +0200
Message-ID: <0D3C3A177CFE4464BF7481BE143EBC01@Clemens0811>
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Subject: LF: RE: RE: RE: TX Toroid Material
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Hi Ken,

For the transformation by the T-pad I've used the well proven TLW3B by Dean Straw
(it was / is(?) included with the ARRL Antenna Handbook).
You can define unloaded Q for inductors and capacitors as well as the power level
and it does all the calculations including V,A,W etc.
As it does not provide not the lowpass T ,only highpass,I've converted the values
to low pass using RFsim for convenience.
Then I did a cross check using a smith chart program by Dellsperger,Smith V2.02,
and the calculated values proved to be spot on.

You may send me your spice simulation per PM and I'll try to find out
what's wrong with it.

73
Clemens
DL4RAJ 
 

>-----Original Message-----
>From: owner-rsgb_lf_group@blacksheep.org 
>[mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Ken
>Sent: Saturday, October 17, 2015 8:52 PM
>To: rsgb_lf_group@blacksheep.org
>Subject: LF: RE: RE: TX Toroid Material
>
>Hi Clements.
>What calculation did you use? I can send you the calculations 
>I used if you
>like the values have been independently checked on LT Spice 1V.
>
>73 Ken
>M0KHW
>
>-----Original Message-----
>From: owner-rsgb_lf_group@blacksheep.org
>[mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Clemens Paul
>Sent: 17 October 2015 17:49
>To: rsgb_lf_group@blacksheep.org
>Subject: LF: RE: TX Toroid Material
>
>Hi Ken,
>
>I believe two of your component values are off.
>I calculate 201µH for the L next to the tubes,625pF for the shunt C and
>1.1mH for the second L .
>For the 201µH L I would use iron powder (Amidon #2), for the 1.1mH #43
>ferrite.
>Use the mini toroid calculator to find the appropiate size 
>regarding number
>of turns and
>allowed flux with safety margin.
>
>73
>Clemens
>DL4RAJ 
>
> 
>
>>-----Original Message-----
>>From: owner-rsgb_lf_group@blacksheep.org 
>>[mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Ken
>>Sent: Saturday, October 17, 2015 5:41 PM
>>To: rsgb_lf_group@blacksheep.org
>>Subject: LF: TX Toroid Material
>>
>>Dear All. I am having problems with the choice of material for 
>>the output network of the 475kHz Valve TX. The network is an L 
>>– C – L, ‘T’ network with an input impedance of 2100 ohms and 
>>a load of 50 ohms, for this configuration the input L is 
>>7.7mH, shunt capacitance is 117pf, and output L is 1.1mH. The 
>>PA design using a 6146 low power or 813 high power work fine 
>>when simulated using LT spice IV. When testing in the real 
>>world using the 6146 there is in excess of 800v rms rf on the 
>>network side of the anode coupling capacitor, but nothing 
>>after the input L. I can only conclude that I using the wrong 
>>type material for the toroids, I used the largest size 
>>(unmarked) toroid which gave me a modest number of turns. I 
>>have checked the Amidon tables and Iron Powder because of the 
>>low AL values, which leaves Ferrite, which mix would you 
>>recommend? The simulations give me output powers 90W for the 
>>6146, and 300W for the 813. I would be grateful for any core 
>>material advice .
>>
>> 
>>
>>Ken Wright.
>>
>>M0KHW
>>
>> 
>>
>>
>
>
>