Is the Dad's knowledge being taught in a tech school or college anywhere? This is science but I fear that it's becoming a lost art. Are there engineers working for the big radio conglomerates with these skills and knowledge sets? I find it all fascinating. In my market, I've almost always preferred the programming on AM radio. Sadly, I know the audience is dying off.
I like using the Enschede webSDR as I'd first seen it on the Modern Rogue channel as they were doing a video on number stations. Recommended If you're casually interested in looking at stuff from a browser.
I discovered this yesterday, I tried to listen to a 60s transistor radio when riding my electrified moped and every time I opened the throttle the radio would make odd noises.
Grew up around hams. Farmers do not use car AM radios in their $1/4 million combines, they have GPS and satellite. You do understand that to restore 2way communications in a disaster they just tow in a portable cell tower and generator with a microwave link and everyone has service again, right? Are you guys still using vacuum tube mono amplifiers to listed to you vinyl?
The real reason...the right wing propaganda dominates most of the AM band. Also, sorry guys, but most of the current forms of communications are now digital and broadcast is FSK or PM or whatever makes the media most immune to noise. The biggest leap in efficiency over the last 30 years is the switching power supply, they are barely compatible with Amplitude Modulation, which again, THAT IS WHY NOBODY USES IT ANYMORE. My dad was Wireless Pioneers, Veteran brass Pounders, operated a ARRL net and an engineer with the FCC. He would be disappointed that you are refusing to move forward.
Being able to accurately compare antenna's signal strength is nice to have. I've gone down the rabbit hole and now own way too many meters. With TV signal strength meters, ones that can measure ATSC and QAM, they will show you the bit error rates and constellation. You can get a really good idea of he health of your antenna and amplifier setup. Gone are the days of being able to see ghosting and intermod on analog TV.
Why go back to 1920s technology when a public packet infrastructure can provide essentially unlimited capacity and far better alerts with rich messaging? And other benefits for rural areas.
Thank you for the 'Tour', gentlemen! All these years, I was under the impression that as long as you never touch the Actual Antenna, you were 'technically safe'! Boy, was I ever misinformed! So just to reconfirm this: If you were to Touch Anywhere on the tower, you can kiss Your Butt goodbye...is that correct, or a slight exaggeration just to keep curiousity-seekers away?!! I'm aware that 'Some Techies' love to impress non-techies, with Grossly Exaggerated Misinformation! True, or Not? Thanks again, guys! KI6CMR Greetings from N. Kentucky.
For AM, the tower *is* the antenna, so your impression is correct, it's just not all towers have antennas-some are antennas themselves :) For FM and other broadcast equipment, you would definitely not want to get too close to the antenna, but (usually) the tower would be safe to touch.
I expect most cars will have digital communications built-in for things like software updates and 9-1-1 distress. Emergency Alerts can be sent out that way, via the necessary digital communications links these cars will have anyways. The alerts can appear as text messages in the cars information center.
I really like how when I just listen to the audio you two sounds so alike it almost sounds like it's the same person sometimes. Or like there's an older and younger version of the same guy having a conversation
This Potomac FSM is built for the MF AM broadcast band. Other versions work on the LW Aviation Navigation band or the SW bands. All on first appearances look identical and all are still in high demand by the radio industry worldwide today as it is one of the few devices around that can give a accurate calibrated repeatable numerical value to the received RF signal strength of a selected radio station, thus the high price.
On receiving am. There is a long wire as the antenna and a ground wire. They are not connected. Loop antenna are connected. With experience, when young a loop antenna don't really work on a radio that is designed for the other. I have also noticed that antenna very with thickness of wires, many are tubes and different materials. What's the deal there. Can I just use a loop copper wire for UHF. Shorter wire of course. Or a VHF with a single wire and ground. If there fundamentally differences what is being used besides then just directional or not. Maybe something is more suitable how the signal is being carried.
This reminds me of my Grandfather. While he was living in northern Ontario Canada around the mid 30's. He would turn his AM radio on after dinner and sit in the corner so he could see up the road for oncoming headlights. He decided not to pay the radio license from the hardware store, so if he saw headlights from a vehicle, he would shut the radio off. The bylaw was enforced by a vehicle that had a directional antenna that could detect the intermediate frequency from the radios when they were turned on. Imagine a knock on your door and someone asking if you have a license for that radio!.☺
re: "hat could detect the intermediate frequency from the radios when they were turned on" Heh. I'll bet they had better results looking for the LO (Local Oscillator) in the radio rather than the IF. ALSO, the LO 'leakage' from an FM radio is MUCH more pronounced (a lot stronger) than the LO leakage from an AM radio.
@@uploadJ That's a good point. He had a directional style antenna and pointed it out the window while driving. I think it was just an AM radio he had at that time. I still listen to a few of the old radio programs on the internet archive.
Hey geerlings! I'm late to the video but I have a few questions aboug the table that I'm hoping I'm lucky enough for you to answer 3 weeks late! I was curious about why the table was named 'ultraHD'. its not a display, nor is it an image, etc so that is an odd name. I was also curious go know whats under that finished wood top? is it solid Oak or is it an Oak sandwich with MDF in the middle?
I went and found the circuit disgram of this unit. This is no ordinary radio…the bloke who designed this was an absolute analog Wizard! I thought…(from “fallout era”) that it wiuld be full of valves, but far from it, almost 80% of the circuit is designed around CA3045 transistor arrays. The only bits where descrete devives sre used is in the audio amp and a j-FET at the RF front end with its fate protected by zeners should someone take a reading right next to a tower with no attenuation swotched in! Another odd feature is it has a Positive Earth, and its rail is -6v that looks to be furnished by four D-cells in series….but the odd thing is, its internal rail is regulated to -6v and the battery can’t be much more than that…so he has used a very low drop out regulator designed around three descrete silicon transistors, two PNP’s in a diffirential configuration and an NPN pass transistor. It is common to see old semicinductor radios built around PNP germanium transistors and using positive earth with these is fairly common practice because then all the transistors’ emitters (the lowest impedance connection on a BJT) can then go to ground by a fairly short path, but this thing has six PNP transistors in it, viz, two in the reg already mentioned, one for the meter and dial lamps, one in the headphone amp and two in the AF amp. all the rest, four descretes and 30 others, five each in six CA3045’s, are all NPN. So the circuit has a strange “upside down” look to it. Looking closer, most of the stages, RF amp, two IF amps, cal oscillator, local oscillator and null circuit are all designed around a diffirential pair with a current sink underneath and a few common emitter gain stages or emitter followers. The RF amp is a very wierd capacitively coupled cascode amp with the drain of the front end j-FET capacitively coupled to the emitter of a subsequent grounded base stage, but has a current sink underneath…..and all this of just 6 volts! So there is barely any headroom to move about. Three things that make this a very different thing from a commercial AM radio are….lack of any AGC, (and this is why you failed to get a good null with the commercialradio…its AGC was working against you), presence of the cal oscillator and null circuit, which a commercial radio lacks…and lastly…designed by an absolute Wizard. The loop antenna of this has TWO active ends that are out of phase, one end goes to the RF amp like in an ordinary radio, but the other end feeds into a common base stage in the null circuit. It is a VERY interesting circuit which looks deceptivey simple st first glance, but the minute you look a little closer you see interesting and mysterious things, and the closer you look, the more you see. One could learn a hell of a lot from this circuit and its clever designer! And that is where the cost is…along with the calibration and lack if drift over time. Ordinary AM radios can have a multitude of evils that a pasted over by the AGC, but here, all is lain bare and has to be spot on, so thanks for making me aware of this marvellous circuit. P.S. If you do go snd look up the circuit, it is drwan like a wiring diagram around the CA 3045 packages which makes in even more confusing to read….as if the positive Earth wasn’t enough….but if you carefully redraw it as diff amps with current sinks underneath and follow the dignal path, that will largely “unscrumple the paper it was drawn on” and allow you to see what a triely clever design it is.
Long post, but a lot of detail. The advantage of using a CA3045 transistor array is the inherent matching, since all devices were fabricated at the same time, so the doping of the semiconductor material is uniform for all devices on the wafer. Matching for gain but also for temperature characteristics.
I listen to AM more often than FM, and I'm still not even 30 yet. It just reaches farther, and when on the highways or torn up backroads for most of the job, it's just easier to tune in and leave it. With FM, your hunting after passing every town; and whether you've got cell service is based on sheer luck. I just wish I didn't have to turn off my 2016 car's spark plugs, and it's 150 amp (max) alternator to get any signal on the MW Broadcast Band during daytime hours; nighttime is better though.
why no one wants to keep am radio is the active suport that is needed as the "Mazda infotainment systems " from 22 in seattle. told us why thies compines dont want to have the am radio.
That's the unit the FCC guy had when checking my Part 15 station. Also our local KELO-AM is 1320. KMOX being 1120 I wonder what 1110 KFAB looks like from your area as KFAB is also 50,000 watts.
I believe it's a Sony ICF-506. I have the ICF-19. They're almost the same radio except the ICF-19 does not have an AC power supply and it uses D cells instead of AA. The ferrite loop is not vertical, the null just isn't as sharp as your Dad is expecting. If you take it outside in the open, you would probably get a sharper null.
Similar devices were used in cable TV distribution systems as well at higher frequencies of course, calibrated at dbm and dbmv, by companies such as Wavetek and Texscan,
