Dear all, the only parts I have bought so far for MF (still beeing engaged in other developments) are two crystals: 6,5536 MHz and 7,0200 MHz, to be mixed with each other. The mixer is another bipola
Hello Stefan, it is all about parts and construction.Picture is from a mixing/PLL VFO I build about 25 years ago.Drift less than 100Hz/hour.The older among us will recognize some of the parts! 73 Vic
Dear Stefan, LF Group, One more question: Currently i use the BF862 since it was on hand. However i could use a normal BF245 instead. I thought it could have an advantage since the housing is bigger
Wow, much to read after a few hours. Thanks to all for the useful informations! One more question: Currently i use the BF862 since it was on hand. However i could use a normal BF245 instead. I though
MF, Another episode about my analog oscillator for MF story. After the hints from the LF group i have now collected a Amidon T50-6 iron dust toroid to wind the coil for a free running analog oscillat
Hi Stefan I may be shot down here but I believe you must avoid toroids as the tuning element in a stable oscillator. It is difficilt to be sure of the mechanical stability of the winding and ferrites
Hello Ken, The thing is, i want to have a very small VFO that consumes almost no power (say < 50 mA at 12V DC). Also i have a f divide by 4 PA and would like to have a VFO that shows the frequency fr
Hello Stefan, for narrowband vfo i get best results with a clap or a seiler,both with big parallel c over the FET.But of course everything depends on the mechanical stability and the quality of the p
Stefan As others have pointed out "6" material is about the best for VFO circuits. Ferrite, especially very high perm material is quite inferior. For securing turns I've found 'old fashioned' polysty
Hi Victor, Am 05.07.2012 19:00, schrieb [email protected]: Hello Stefan, for narrowband vfo i get best results with a clap or a seiler,both with big parallel c over the FET.But of course everything
Mal, Stefan et al., You wrote: ... Try permability osc tuning like Collins use instead of variable condensers, maybe even a valve osc. ... Of course the best choice. But 1. you need an iron-dust cyli
Jay, what is "MEK" which is referred to in the link you've given? '...What I did was to dissolve polyfoam shipping material in a mixture of MEK and xylol. ' 73 Clemens DL4RAJ Stefan As others have po
Dear Stefan, Yes. xtal 7,02 MHz will run stable, and xtal 6,5536 MHz must be pulled down by 12,6 kHz to 6,5410 MHz. A coil in series to the crystal and the tuning capacitor will do this, in its simpi
Stefan, what about a huff&puff oscillator (http://www.hanssummers.com/huffpuff.html) ? 73, Rik ON7YD - OR7T ________________________________________ Van: [email protected] [owner-rsg
Dear Stefan, LF Group, In my experience, the oscillator circuit topology is usually less important than the component values used, the type of components, setting the bias current in the transistor,
Even a Nuvistor or miniature wired in valve only 5mm x 15 mm , ARC52 was full of them G. From: mal hamilton Sent: Saturday, July 07, 2012 10:32 AM To: [email protected] Subject: Re: LF: RE
Hello again, It is a bit disapointing. The oscillator is drifting several 100 Hz when looking to the divide by 4 side, i.e. the PA output i.e. close to 475 kHz. Does someone have the circuit of the 1
Hello Stefan, Reichelt carries Amidon powdered iron cores, but you probably know that already. When you have to order, the T-68-6 size might be a little better. 73, Roelof, pa0rdt
Hello Stefan, i fully agree with you,it is all about the fun of doing experiments,if the technicues are modern or oldfashioned doesn,t matter. 73 Victor PS; I work to live,I don't live to work --Oors
