Hellraiser Transmitter Project - Photo by Hans Summers
Hello again. I would like to share another resource that will inspire, inform, and astound. Hans Summers, G0UPL, is an Electronic Wizard of the Twelfth Degree (see the International Brotherhood of Electronic Wizards Handbook for further information). He has built a website that abounds with inspiration. His projects are visual and functional. He likes to use tubes and will spurn convention to create a visually appealing project. This is art. The amount of information is sure to keep you busy and should be bookmarked for reference. I am interested in his extensive information on Huff and Puff Oscillator stabilizers and identifying crystal parameters. He builds his own test equipment and documents so that we can follow in his path. Several QRSS projects are detailed. I have added QRSS to my list of future projects. Thank you Hans, for sharing a lifetime of experience at HansSummers.com. 73
Robin
NORCAL S9
When I started planning the Hendricks BitX20a Project there were several pieces of test equipment that I found would help. One of the needed items was a signal generator. NorCal QRP Club makes a fine kit with easy to follow directions for those such as I, i.e. directionally handicapped. It has four crystal controlled frequencies. I needed 11Mhz so a quick trip to Sky Craft (that was a joke) supplied a crystal that was exchanged for the supplied 10Mhz crystal. The S9 kit is a mix of surface mount and through-hole construction. It also has an attenuator that drops the signal to an S1 level. I am guessing this could be helpful when adjusting the receive end filters. Upon completion I found the signal to be very weak and when I switched in the attenuator the signal disappeared. I took it to my Elmer, K4DF, and he described the circuit to me as we hooked it into his HF rig. When he finished showing me the oscillator and attenuation circuits he suggested I check the solder joints in the oscillator section. A magnifying glass and some quick soldersmoking solved the problem. This kit will fit in a Altoids tin, but I do like looking at it. These kits are great fun and provide practice with an iron. Soldersmoking rules. 73
Robin
KC4ZVW, Dave, commented on my last post and ask some basic questions that started me thinking. Does it work? It leads me to why I am building the BitX20. I have a strong desire to learn electronics. This project allows immediate feedback on each section that is completed.
When I completed the audio amp, I needed to find an input source to check it out. Travis, my son, and I built a crystal radio with an audio amplifier circuit. This Fox Delta design is made to learn with and has the ability to separate the audio amp from the crystal radio. I fed the signal into my BitX and it worked. I have already received the local AM station through my Bitx. DAVE, it works.
Then I built the Mic Amplifier. By jumping a signal and powering the audio amp section I was able to hear my own voice through my small amplifier setup. Yes it does squeal when you get the mic near the speaker just like the real audio setups, and yes I played with all the feedback noise I could create. That worked too.
I have completed all soldering on the radio. A radio is an oscillator that allows us to throw electromagnetic waves through the air and catch them at a different location. This radio has two oscillators. One is a carrier oscillator that is a 11.00001 Mhz, and the other is a variable oscillator, VFO, that is close to 3.0 Mhz. When combined, the frequency that adds up is near 14. Mhz, the 20m Band! Well , there’s a problem Dave. First, I have both signals oscillating and measurable although the VFO is only variable by 3.5 Khz. Not enough to qualify as a VFO. On this radio I will need a couple of hundred Khz to cover a portion of 20m phone band. I soldered in a different variable resistor and air variable capacitor and the oscillations stopped. I will go back on that change. Second, I am unable to find the 14. Mhz signal. I have unbalanced the modulator to let the carrier signal through to the mixer near the VFO and where I feel it should be, it ain’t. There I is. Stuck again.
Dave, does it work? Wonderfully! I am learning radio theory, trouble shooting, soldersmoking, and burning my fingers. LIFE IS GOOD. Oh… the radio, well I’m sure it will work when I am done. 73
Robin