-- Behind the MXM there is a nice box marked "Diode Detector" I opened it up and there is just a solid state diode and a 50 ohm resistor to ground. Box may be useful.
-- I got a couple of books: "Weekend Projects" 1979 from ARRL, and "A History of QST -- Volume 1 Amateur Radio Technology 1915 - 2013" 2013 from ARRL.
-- On top of the Weekend Projects book you see a "Crystal Holder" from Gross Radio of New York City. W1UJR has some good history on this company: https://w1ujr.com/written-word/gross-radio-company-circa-1931/ This device seem to be intended to hold in place a raw piece of quartz! Cool.
-- To the right of the books there is a serious-looking VFO. One dollar! Deal! It is a CB VFO, but the markings say it puts out 5.44 to 5.99 MHz. So it should be useful. The dual speed dial is very nice.
-- Above the VFO is a nice step attenuator from the "Arrow Antenna" company of Loveland Colorado.
-- Further to the right are some Electric Radio and Antique Wireless Association magazines that Armand WA1UQO gave me. Really nice. The AWA mags have a very thoughtful piece (warts and all) on Jean Shepherd. And the ER pile has an article by Scott WA9WFA that mentions my work on the Mate for the Mighty Midget receiver. Thanks again Armand!
-- I also got some ADE6+ surface mount mixers. The price was right!
Thanks to VWS for putting on this great hamfest!
Posts
I gave Gemini a hypothetical situation, and asked something I'd been thinking about for some time. If you could go back to when there was no man-made radio transmissions, with a DC receiver and a couple of friends who would transmit, being at different locations. Would a bandpass filter be necessary? If fact I asked. Would the bandpass filter be a negative? Possiblity knocking down some of the desired frequency. I didn't know how well Gemini would take my lengthy hypothetical and questions. It did well.
ReplyDelete"You're right, this is a cool hypothetical scenario! Here's the breakdown of the bandpass filter in your time travel ham radio situation:
Without a Bandpass Filter:
Yes, the receiver could still work: In the absence of any man-made radio signals, the receiver would still function even without a bandpass filter.
Potential for Noise: However, the lack of a filter makes it susceptible to picking up all sorts of electrical noise from the environment (atmospheric noise, power lines, etc.). This noise would be present across a wide range of frequencies and could potentially mask the desired signal from your fellow time travelers.
With a Bandpass Filter:
Improved Signal-to-Noise Ratio: A bandpass filter tuned to the specific frequency (7.3 MHz) of the transmission would significantly improve the situation. It would allow the desired signal to pass through while attenuating everything else. This would make the signal from your companions much clearer and easier to hear amidst the background noise.
So, the bandpass filter:
Isn't strictly necessary for the receiver to function in this specific scenario with no competing radio signals.
Would significantly improve the listening experience by reducing noise and making the desired signal from your fellow ham operators much clearer.
Adding the Filter Wouldn't Attenuate the Desired Signal:
A properly designed bandpass filter centered at 7.3 MHz would allow the signal from your companions to pass through with minimal attenuation. So, including the filter wouldn't weaken the desired signal, it would only strengthen it relative to the background noise.
Importance of the Bandpass Filter:
Even in a seemingly ideal situation like this, the bandpass filter plays a crucial role in enhancing the receiver's performance by:
Simplifying reception: It makes listening easier by focusing on the specific band of interest, eliminating the need to sort through all the background noise.
Improved sensitivity: By reducing noise, the filter effectively increases the receiver's sensitivity, allowing weaker signals to be heard more clearly.
In conclusion, while the receiver might technically function without a bandpass filter in this particular scenario, including one would greatly improve the listening experience by filtering out unwanted noise and making communication between your time-traveling ham buddies much clearer."
Bill. What's that behind the SuperRX/TX 40 transceiver to left of the diode detection, with all the torroids? Is that part of what you picked up at the hamfest?
ReplyDeleteI realise now. It looks like the version 2 of your transceiver.
ReplyDeleteDid someone say "T50-6"? Looks like them.
ReplyDelete