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The best I can do would be jpeg photo of hand drawn paper page. Even that takes some effort as only one PC supports USB and this is not that one. All my schematic capture cadd stuff runs on VAX/VMS

Allison Would it be possible for you do a quick schematic of the changes and store it in the FILES section of this forum? That way it will be available for others who might not understand all that

One of the things I didn't like in the 20m proto BITX I'd built was the presence of audio getting into the IF amp on transmit and IF noise in to the audio on recieve. I'd gone the route of adding

Hi, 2mw is very low from the driver. Mine I see nearly 1mw at the output of the bandpass filter (L1, L1,L3). The driver stage brings that up to near 300mW on mine. I don't use the IRF510 as the

Hi Milarepa, based on my measurements, it is only a few mw, so the oposite of what Allison measured. I searched for you in the older postings (I have often the feeling that older messages are not

Based on my proto 300mW is correct. If there were 300mV the power would be about 2mW which is way to little. Allison KB1GMX

Folks I am working from the (c)2004 circuit on Ashar's web page and have very low output from PA. I am using cheap general purpose transistors (ME4003) and changed pre-driver for 2N2222. Better but

Dear forum, I have read somewhere from the posting messages that the output of pre driver should be about 300 mWatts, but I read from the article it should be about 300 mVolts. Which is right

Hi Chris, Rather than guess at Gautams question it is easy to ask. Saves giving multiple conflicting answers. I may add my favorite "cheap" Varactor [tuning] diode is 1n4007 rectifier. It also

Hi! Arv is quite right. Here we also took a similar route. First was the need for a cheap common PSU so we selected a portable BW TV transformer sec abt 20V AC unloaded around 1.25amp. Unreg DC goes

Gautam I am assuming that you are using the same size VFO inductor and capacitors as specified by Farhan. If you are using the original design with the 36V zener diode as a VFO fine tuning

gang capacitor my VFO shows 4.000 to 4.180 MHz(when trimmer shifted to 4.000MHz) and after tuning Trimmer(shifted to 4.150MHz) it shows 4.180 to 4.410Mhz. entire range i.e. 4.000 to 4.400MHz. Varies

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

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

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

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

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

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)

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

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