| Keith C. Perry via plug on 20 Oct 2022 14:36:52 -0700 |
[Date Prev] [Date Next] [Thread Prev] [Thread Next] [Date Index] [Thread Index]
| Re: [PLUG] [OT] SW radio question |
Nice unit Steve. I love MFJ stuff. I didn't know about this one though. If I can also throw out a recommendation for the hams among us, I highly recommend the MFJ-971 manual tuner, which requires NO POWER (unless you want to backlight the screen and even then its very littel). You can't go wrong pairing this with a [QRP] transceiver to work regionally (i.e. inside the skip zone) so you know what is going on around you. ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ Keith C. Perry, MS E.E. Managing Member, DAO Technologies LLC (O) +1.215.525.4165 x2033 (M) +1.215.432.5167 [ http://www.daotechnologies.com/ | www.daotechnologies.com ] ----- Original Message ----- From: "Philadelphia Linux User's Group Discussion List" <plug@lists.phillylinux.org> To: "Philadelphia Linux User's Group Discussion List" <plug@lists.phillylinux.org> Sent: Thursday, October 20, 2022 5:15:07 PM Subject: Re: [PLUG] [OT] SW radio question Eric Lucas via plug said on Wed, 19 Oct 2022 14:23:36 -0400 >I know this is off topic however there are quite a few ham radio folks >here and I need some knowledgeable advice. > >I'm planning on buying a portable AM/FM/SW radio and I'm down to these >two Sangean ATS-909X2: [snip the two Sangeans] In my metal garbage can, which serves as the best Faraday cage I can muster, sits my MFJ-8100k, which I built as a kit. See https://mfjenterprises.com/products/mfj-8100k . It can be bought for more money fully assembled: https://mfjenterprises.com/products/mfj-8100w . It's about 7 inches by 6 inches by 2 inches, approximately. It's powered by a 9 volt battery, so for SHTF you'll need several 9 volt batteries. Here's the manual: https://static.dxengineering.com/global/images/instructions/mfj-8100k_mm.pdf This is a regenerative radio, just like from the 1930's but transistorized for longer life (if your metal garbage can can keep out the EMP). As people have stated, you'll need a good antenna (50-100 feet of stranded bell wire thrown up into a tree would be good enough). This radio won't pull in stations as well as good Sangeans and Grundigs, etc. You need some skill operating the regeneratation and frequency dials, almost simultaneously. There is definitely some hand-capacitance. With a 30 foot indoor wire antenna I can only pull in strong stations because there's so much electrical noise in our house, but that's true of all my shortwaves. If the neighborhood power goes off, all that electrical noise goes away. The MFJ-8100 is best listened to through headphones. The dial is marked for frequencies, but the dial is small, the frequencies are approximate, and are subject to adjustment. So you're probably asking yourself why my metal garbage can contains this radio... It's a simple circuit on a single layer, one sided board. No digital stuff to go bad. None of these endless rotate/click controls, which inevitably go bad after a few years. Only one integrated circuit in the whole thing: A LM386 op amp for audio amplification. A *real* air gapped tuning capacitor that you can blow dust out of, instead of these wax-separated tuning capacitors or PLL circuits. No dial string, it's a geared Vernier variable capacitor. If you could scavenge transistors, resistors, and diodes you could probably repair this thing; don't try this with a modern Sangean. Like all regenerative radios, it can do CW and SSB natively, although it will probably sound a little donald-ducky unless you're better with frequency/regen adjustment than I am, but it's understandable. It covers a heck of a lot of frequencies, though it's not continuous frequency coverage. For a run-of-the-mill local disaster like a hurricane or earthquake, what you need is a battery operated FM radio. But for bigger, longer lasting stuff like financial collapse, EMP, civil war, asteroid strike or Yellowstone mega-eruption, a nice, simple, small regenerative receiver might be just what you need to hear what people 1000 miles away have to say. Be aware that MFJ sells transmitters too, although if you transmit you're letting others know where you are. I think a set of FRS walkie-talkies might be appropriate too, if not used frequently. I'd get the ones that work with real batteries, not rechargeables. Like I said, my MFJ-8100k is kind of a recommendation out of left field, but that's what I have in my metal garbage can, along with my backup disks and some batteries and a very nice AM-FM radio. SteveT Steve Litt Summer 2022 featured book: Thriving in Tough Times http://www.troubleshooters.com/bookstore/thrive.htm ___________________________________________________________________________ Philadelphia Linux Users Group -- http://www.phillylinux.org Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce General Discussion -- http://lists.phillylinux.org/mailman/listinfo/plug ___________________________________________________________________________ Philadelphia Linux Users Group -- http://www.phillylinux.org Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce General Discussion -- http://lists.phillylinux.org/mailman/listinfo/plug