Re: need help for vfo
Hi,
I think the tuning range is found to be to small.
Likely because the tuning capacitor does not have enough capacitance.
(the LC combination defines the frquency and if the L is fixed, only
the C
By
Chris van den Berg
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#922
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Re: need help for vfo
Hello,
First the transistor used. The 2n222a or 2n3904 are excellent for
this type VFO.
I have tried to understand what problem you are having. I suspect
the range of tuning 0-230khz is either
By
ajparent1 <kb1gmx@...>
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#921
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need help for vfo
hi,
in my bitx20 vfo frequency is 4.000 to 4.230MHz or trimming the trimmer i found 4.200 to 4.430 (i.e 0 to 0.230 MHz tuning range). aftyer several changing in coil and various types of capacitor(2j
By
kumar gautam <fromgautam@...>
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#920
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Re: need help for IRF540
Hi!
Go ahead with 540. Let me know someone coming this side 510 is available at Lucknow.
73
Rahul VU3WJM
kumar gautam <fromgautam@...> wrote:
HI,
HERE IN MARKET IRF510 IS NOT
By
Rahul Srivastava <vu3wjm@...>
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#919
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FW: Re: IRF510 on higher voltage?
Hello Hans,
I do hope you got my initial response. The blocking may be enroute,
it's not anything I can control. Do try to reply to the arrl.net
address rather than direct.
High power (greater
By
ajparent1 <kb1gmx@...>
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#918
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Re: need help for IRF540
Hello,
That IRF540 will be very difficult to drive with increasing frequency.
The input will be very reactive and will require a more complex
network to get the needed RF power (and voltage)
By
ajparent1 <kb1gmx@...>
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#917
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Re: need help for IRF540
Hi Kumar,
The datasheets give the following parameters:
IRF510: RDS = 0.54 Ohms; ID(continous) = 5.6 A; maxPower = 43W; Input
capacitance = 180 pF
IRF540: RDS = 0.077 Ohms; ID(continous) = 28A; max
By
Heinz Schnait <oe5eep@...>
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#916
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FW: Re: IRF510 on higher voltage?
Apologies list, for the bandwidth - I am having some trouble emailing
Allison on private email. Seems I am blocked somewhere :-(
73 Hans G0UPL
http://www.HansSummers.com
By
Hans Summers <Hans.Summers@...>
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#915
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need help for IRF540
HI,
HERE IN MARKET IRF510 IS NOT AVAILABLE, ONLY IRF540 IS AVAILABLE. ANY ONE HELP ME THAT IRF540 IS EQUIVALENT OF IRF510 OR I CAN SUBSTITUTE THIS FET.
WITH 73'S
DE KUMAR
By
kumar gautam <fromgautam@...>
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#914
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Re: IRF510 on higher voltage?
Good old crush and plaster ah, rather cut and paste. ;)
Oh well, you found it and dont forget there is information in
part 2.
linear...something
might
Since you ask. I've done it on paper and it
By
ajparent1 <kb1gmx@...>
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#913
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New file uploaded to BITX20
Hello,
This email message is a notification to let you know that
a file has been uploaded to the Files area of the BITX20
group.
File : /Spectrogram517-4filter.exe
Uploaded by : vu3wjm
By
BITX20@...
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#912
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Re: building filters
Hi Chris and Julius,
In the experiments with 9MHz filter the crystals turned out to be
about 9.015MHz. With the BFO exactly on 9.005 MHz I get both sides of
the filter and I can determine the
By
Ruud Jongeling <pe2bs@...>
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#911
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PC spectrum analyser.files
The Gram zip file have about 250Kb of size and I can?t upload now I
will try later...
73 PY2OHH
By
Miguel Angelo Bartie
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#910
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Re: building filters
Hello friends
I am building another BITX40, my other with two bands work great but
there are many external boxes to plug togheter...
If you are looking articles for mesurenents of filtres by sound
By
Miguel Angelo Bartie
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#909
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Re: building filters
Hi Julius,
that is the fun, nothing to adjust in advance, just connect it (I
used two resistors as a signal attunuator)and watch the screen (if
you receive enough noise).
If you do not receive
By
Chris van den Berg
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#908
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Re: building filters
Hi!
Elecraft has often published doc related to SSB filter alignment using Sectrogram:
www.elecraft.com/Apps/new_fil_docs/k2_cw_gram.pdf
Excellent page here not only provides the uncrippled
By
Rahul Srivastava <vu3wjm@...>
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#907
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Re: building filters
In German Funkamateur was published schematic for hf noise generator
and described metod of mesurment by using sondcard lf spectogram. I
am sorry that it is again in russian but can be easily
By
Max
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#906
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Re: IRF510 on higher voltage?
Allison
That URL for the MOSFET HF Amp is actually:
http://www.cnham.com/pdf/amp/irf510/HF_use_FET_1.pdf
I wonder if anyone has ever tried a grounded-gate MOSFET linear...something
much like
By
Arv Evans <arvevans@...>
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#905
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Re: IRF510 on higher voltage?
There are at least two or more designs using IRF510s in push
pull form. The power out was in the 30-45 watt range for two devices
running at 24V through 10M. This is reasonable for the class
By
ajparent1 <kb1gmx@...>
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#904
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Re: building filters
With the software and connecting the output of the AF amp to PC, i wonder where do we set the BFO to find out the shape of our filter, assuming that we do not know the center frequency yet, or
By
Wijaya, J. <iyung_w@...>
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#903
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