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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 · #922 ·
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@...> · #921 ·
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@...> · #920 ·
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@...> · #919 ·
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@...> · #918 ·
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@...> · #917 ·
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@...> · #916 ·
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@...> · #915 ·
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@...> · #914 ·
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@...> · #913 ·
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@... · #912 ·
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@...> · #911 ·
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 · #910 ·
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 · #909 ·
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 · #908 ·
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@...> · #907 ·
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 · #906 ·
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@...> · #905 ·
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@...> · #904 ·
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@...> · #903 ·