Fisher made at least two of their own MPX adapters.
Fisher MPX-65 FM Multiplex adapter
Fisher MPX-100 FM Multiplex adapter
Fisher MPX-65 FM Multiplex adapter
Fisher MPX-100 FM Multiplex adapter
19 and 38 KHz inductor:
https://www.roehrentechnik.de/html/nf-spulen.html
10.7 MHz (and 455kHz) inductors/transformers:
https://www.roehrentechnik.de/html/zf-bandfilter.html
other 10.7 MHz and various other frequencies' inductors:
https://www.roehrentechnik.de/html/mini-filterspulen.html
There are more AM/MW inductors and transformers on this site as well as audio (valve) transformers etc. The site is in German so a bit of exploring and translating is needed but I presume one can always send an e-mail to ask for details if in trouble.
https://www.roehrentechnik.de/html/nf-spulen.html
10.7 MHz (and 455kHz) inductors/transformers:
https://www.roehrentechnik.de/html/zf-bandfilter.html
other 10.7 MHz and various other frequencies' inductors:
https://www.roehrentechnik.de/html/mini-filterspulen.html
There are more AM/MW inductors and transformers on this site as well as audio (valve) transformers etc. The site is in German so a bit of exploring and translating is needed but I presume one can always send an e-mail to ask for details if in trouble.
TBH, that won't help the thread starter because (excempt experimental and ham radio) the MPX decoder only applies to FM radio.
There was an AM radio stereo decoder system in the US, obviously working on different principles.
Quite possible but since AM radio doesn't provide the bandwidth, the frequency range didn't even close reach the standard FM 15kHz. It was very susceptible to interfering signals and because of the needed bandwidth, its reach was severely limited. The wider the bandwidth, the lower the signal on the receiver. Because of the massive drawbacks of the AM modulation, it was never actually relevant in broadcast history. That all won't help the thread starter in any way though.
That's surely true but that doesn't affect the fact that represents the radio bands and stations of 1961, which have drastically changed, especially the selectivity (filter slope) and the station/frequency density became so much more demanding. A receiver from the 60s will not perform well in any way with the modern use of FM unless you've got a high gain yagi antenna with rotor servo and elevation which excludes off-center frequencies alone from the antenna (arial?) reception directivity. And that's what I'd suggest if you use old receiver circuits, use very narrow/high gain antennas to compensate for the lack of old receiver concepts.
Here in the USA, my 1960 Dynaco FM-3 (and other good FM tuners of that era as well) works beautifully.
No elaborate antenna is needed, and I use rabbit ears only. Small towns far from cities may have problems.
FM broadcast was never intended for long distance reception.
No elaborate antenna is needed, and I use rabbit ears only. Small towns far from cities may have problems.
FM broadcast was never intended for long distance reception.
In Europe that's a completely different issue. And I am sure in some areas of the US it's not better at all. Be happy with your radio situation, here in the EU it's on the brink of the FM radio shutdown for good.
The AM/MW inductors were mentioned by the by - in case anyone is also interested in them.
The rest of the inductors were for FM radios though, assuming they are still available. This site has been there for many years, though I have never had the chance to have business with them.
I have not been able to find any other site that offers FM radio inductors today, for valve radios, to this day.
Not yet. Though many countries are only too happy to ditch it and jump on the DAB bandwagon.
I wonder what they'll ditch DAB for next. I guess internet radio will be available everywhere soon but it's complete chaos at the moment.
That FM is still alive in the USA is quite a miracle, although there is probably a reason for it. It also means that FM will not disappear overnight in Europe.
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By the way, anyone interested in the inductors on the
https://www.roehrentechnik.de
or valve FM tuners and MPX decoders in general, might also find it interesting to visit the site of
https://www.jogis-roehrenbude.de/
There is a diy valve FM tuner and MPX decoder in it, among other things, and plenty of links as well. Quite a treasure trove of information.
https://www.roehrentechnik.de
or valve FM tuners and MPX decoders in general, might also find it interesting to visit the site of
https://www.jogis-roehrenbude.de/
There is a diy valve FM tuner and MPX decoder in it, among other things, and plenty of links as well. Quite a treasure trove of information.
Yes, that's right. But the DAB broadcasting is extremely disappointing, to say the least. The main problem is, because of wider bandwidth for the stations, it costs a lot more, the sound quality is usually vastly inferior to the FM counterpart. And the most DAB receivers are optimized for minimal cost instead of good sound for affordable price or even high price/top quality. And that's the downfall of it, no questions asked. Every cell phone can deliver much better quality, bandwidth, informations and precision, DAB is obsolete practically from it's introduction and gives not one single advantage. My dad insisted on getting a DAB receiver and they were either okay-ish for a obcenely overpriced product or were simply so cheaply made even a used 5 bucks eBay tuner/receiver/car stereo sounded so much better you'd think the DAB receiver came out of a bubble gum vending machine, it's not even funny anymore because between these extremes there's not one acceptable one on the market.
I believe, in the US, radio stations, FM radio stations, are not as tightly packed as they are in Europe. There are also many more good FM valve tuners to choose from, most of which never made it to Europe. Of course good valve FM tuners still command a hefty price today. In Europe there are mostly many valve radios but not that many valve tuners. Some of these radios are of course very good but including them in a modern stereo system would be a rather cumbersome solution.
The problem is, most consumers either don't know this, don't care to know this or just plainly are not avid radio listeners. So, when they get a new car, they don't care what kind of radio it has (which is invariably DAB or FM plus DAB). Also, since most young stereo system owners really go for miniaturization, portability and low cost these days (their attention and spending habits being directed elsewhere), they may try out the odd DAB tuner (which might come packaged in a streamer all-in-one device) but, other than that, they will not really care about radio itself. They do not realise what a world without radio, i.e., AM and, to a lesser extent, FM radio, will be like. A world where DAB and software radio have dominated is really a world without radio. When people start ditching their old AM/FM radios, it could become a very scary place indeed.
You are right, the density is so much lower. and I agree, while there are really good PLL FM recievers, the tube and analog FM tuners sound almost always so much better but since their selectivity and side band suppression is that low, you often just can't use them on the station you want to listen to. Having an analog radio/tuner got almost always one major advantage, the digital noise of PLL or micro controller will never appear. I really appreciate a high selective tuner and the comfort of the station memory etc functions but that can't outweight the sound qualities of an analog tuner - as long as the station reception situation and its sound quality aren't interfered with. Or if the tuner is that extremely high end is on an equally high level. But these units go for moderate to high 4 figure numbers, it's not even funny anymore to even search for them on any selling platform.
It's all about making money, which can't be a good thing. Even in the FM band, as a rule, there are hardly 3-4 good radio stations in any given location that are worth listening to.
As to it being very quiet, sure but it does cut out completely when there's no signal plus you don't need it to be this quiet when you are in a car. When you're at home on the other hand, a good live FM broadcast used to be the best thing in audio (provided it was done properly and a good tuner was available). Nowadays, of course, it's all digitally processed anyway so one could argue we are already half way there on the way to digital radio, although it would be a weak argument. 20-20kHz is not really needed: most systems cannot reproduce down to 20Hz and nearly all adults over, say, 40 cannot hear above 13kHz.
I haven't checked lately. I am a bit surprised to hear that.
I think most well known tuner models are off the market now as their owners have probably decided they might as well keep them for as long as FM is still alive. But a few years back I used to see broadcast tuners go for pretty cheap prices - much cheaper than a decade ago. Then again, there's not that many of them out there and they are not really consumer gear. The beasts from the '70s or '80s of course are always going to command a very high price. I was lusting after a KT-917 for donkey's years and eventually gave up as I never came across it more than a couple of times and neither of these times did it come with a price tag I could find tolerable.