[Lowfer] Lowfer KE

[KA4SEY]

Hey John, how is your computer setup doing? I meant to tell you, I took the LPF out and both transistor are doing good. I put a 10W 50 ohm resistor from the output to ground and supplied 24v to the circuit and got 75ma to the finals. It was putting out a whopping 1.8 watts! The resistor even got got. I'm excited! Now with it out of line and back at the antenna it's on a 13.8v power supply with the same configuration and I was getting 35ma to the finals. I believe that's about 450mw. But looking at the signal here on the radio it's much stronger. I even picked the tub up and sat a milk crate under it and now it's a strong 20 over. So both of those helped. I will try the configuration you told me to try today and see how that goes. I might try the thing on 24 volts and see if the signal increases.KaseySent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------From: John Hamer <wilbur0611 at gmail.com> Date: 11/22/20  9:38 AM  (GMT-05:00) To: "Discussion of the Lowfer (US, European, & UK) and MedFer bands" <lowfer at mailman.qth.net> Subject: Re: [Lowfer] Lowfer KE I Believe he has the capacitors on the oscillator and they are just not onthe schematic he posted.  I went through datasheet with him over the summerand calculated the proper capacitor values.RegardsJohn HamerLowfer JHOn Sun, Nov 22, 2020, 9:28 AM KA4SEY <ka4sey at gmail.com> wrote:> Thank you John, I will add those capacitors on in the future and make any> other changes. Like I said I'm going to try another configuration with the> coil today to see if it will do any better. I will hopefully find an> ammeter which would help me a lot. Thanks againKaseySent from my Verizon,> Samsung Galaxy smartphone> -------- Original message --------From: J D <listread at lwca.org> Date:> 11/22/20  2:27 AM  (GMT-05:00) To: lowfer at mailman.qth.net Subject: Re:> [Lowfer] Lowfer KE Kasey, it would appear from your schematic that a few> components may be missing, thereby preventing your oscillator from being as> stable as it needs to be. This same situation is found in a commercially> made sorta-kit rig for 22 meters, and beacons using it there can often be> identified by their tendency to wander or even outright jump around in> frequency from day to day.A Pierce oscillator needs capacitance from both> legs of the crystal to ground as part of a phase shift network. There is> stray capacitance present, of course, without which it would not oscillate> at all; but that is neither of sufficient magnitude nor stability to ensure> reliable oscillation at the design frequency of the crystal. A good> starting value for capacitors for a typical 3 MHz parallel resonant crystal> would be 27 pF each.In addition, there n>  eeds to be a series resistor between pin 10 and the crystal. It serves> three functions that each affect frequency stability to a certain extent:> it isolates the crystal somewhat from the complex impedance of the gate> output, it limits current and thereby power dissipation in the crystal, and> it is part of the phase delay network. As a rough first approximation, I'd> suggest 1 K, maybe as high as 2.2 K.Finally, the shunt resistance across> the crystal could be a little higher in value for 3 MHz operation, such as> 3.3 M to 4.7 M. It's not terribly critical, but it is preferable to operate> it with as high a value as will allow for reliable startup. Lowering the> operating Q of the crystal with a low parallel resistance could allow a> crystal to jump too easily between primary resonance and any secondary> resonance modes it may have.These comments are some basic rule of thumb> guidance. For more detailed treatment of Pierce oscillators implemented> with logic gates, I believe Crystek s>  till offers this article:> https://www.crystek.com/documents/appnotes/pierce-gateintroduction.pdfJohn> Davis______________________________________________________________Lowfer> mailing listHome: http://mailman.qth.net/mailman/listinfo/lowferHelp:> http://mailman.qth.net/mmfaq.htmPost: mailto:Lowfer at mailman.qth.netPost> must be less than 50KB total for message plus attachment!This list hosted> by: http://www.qsl.netPlease help support this email list:> http://www.qsl.net/donate.html> ______________________________________________________________> Lowfer mailing list> Home: http://mailman.qth.net/mailman/listinfo/lowfer> Help: http://mailman.qth.net/mmfaq.htm> Post: mailto:Lowfer at mailman.qth.net> Post must be less than 50KB total for message plus attachment!>> This list hosted by: http://www.qsl.net> Please help support this email list: http://www.qsl.net/donate.html>______________________________________________________________Lowfer mailing listHome: http://mailman.qth.net/mailman/listinfo/lowferHelp: http://mailman.qth.net/mmfaq.htmPost: mailto:Lowfer at mailman.qth.netPost must be less than 50KB total for message plus attachment!This list hosted by: http://www.qsl.netPlease help support this email list: http://www.qsl.net/donate.html