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Messages - ThaDood

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Well, if you do go inside, the most common problem that I've run into with several of these radios is that ribbon cable that half-ass plugs into an IC socket. Every time, (Due to dissimilar metals.), those pins and contacts are found corroded. If you find that, the quick fix is to clean all that out with 91% isopropanol, let dry completely, plug-in that ribbon cable, and see if that worked. However, that corrosion will happen again. On several radios, including my own, I've hard soldered those ribbon cable pins to the contacts of that IC strip. Mine still works +25 years later. 

Huh? / Re: Is Bomar Crystal the last one in USA?
« on: August 18, 2020, 1757 UTC »
Thanks Chris!!!! Well, I still will get DDS OSC's for various projects, but replacement crystals for various older rigs and even TCXO's for a couple of Kenwood rigs that I want to tighten the FREQ spec's on, (Like a TS-50S, a TS-60S, and a TS-711A.). Yes, there are replacement TCXO's out there that some places are offering for stupid money, but why use a middle man, when I can just order what I want from the source?

Huh? / Is Bomar Crystal the last one in USA?
« on: August 18, 2020, 0606 UTC »
Yeah, is this the last domestic crystal manufacturer left. And do they actually make crystals here?     http://bomarcrystal.com/

If your DX-440 had the Front End blown, it would be incredibly deaf, with the exception of super strong signals, like in the millivolts. As far as having a lower supply voltage affect your radio's performance, very possibly. The PLL is voltage controlled and the AGC might act weird on you, besides that initial loud PING that they'll all do for a 1/2sec when tuning into a very strong AM carrier. (Which has been one gripe that some have had about the AGC with this radio. Some folks have actually gone as far as modifying that. I have not.) If your AGC is a little wacky on strong signals, try adjusting that RF Gain knob. As far as SSB HAM's sounding muddy? Some of those ops have very low toned audio, (And some of them sound damn near broadcast quality sounding on my Kenwood rigs.), and may sound funky with a receiver with just a BFO. That, and each station maybe slightly off FREQ as well. I'm just brain storming with what I do with mine on various stations.

Looking at that crammed schematic in the .PDF Service Manual, that 1st Front End transistor is a PNP BJT. Thus far, no static problems with the Front End of my radio going on +30 years. So, at a gander, I'd say that Front End on the DX-440 / ATS-803A is not as static sensitive as the Sony ICF-2010's. That said, it's still pretty sensitive, compered to other portables out there, for weak signal hearing. So, if you put that portable to a longwire, 80M dipole, Windom, etc., the added protection of opposing 1N4148 diodes, or something less noisy, for spikes beyond .7V, is not a bad idea.

Amateur Radio / Re: 2M SSB
« on: August 15, 2020, 2049 UTC »
Heck... Put that rig to a VHF/UHF TV antenna and rotate that around, with a +20dB VHF/UHF preamp, and then you'll really see what you can hear on 144.200USB and even 432.100USB / CW. If you should use a TV antenna to TX, minus the preamp in place, you may get away with around 20W PEP. Higher than that and most likely the 75 / 300 Ohm TV baluns will fry. Can be done, though. It wouldn't be hard to construct your own 3 element 2M SSB beam, or even an Omni,   https://www.sekarc.net/2016/01/easy-2-meter-ssb-loop-antenna.html      ,      http://www.hamuniverse.com/2ssbyagi.html    Yeah, that shows 6 element, but 3 can be done.  I make a 4 element PVC and copper #10AWG beam in the mid-90's and talked all over the NE USA States and Canada with 140W behind that.

Neat chanito! The Audio MOD's that I also did on my ATS-803A include changing the resistors to that DIN socket connection, but damned if I can remember what the value of those resistors were. That fixed audio tap connector is nice, but very low level, so I changed the resistors internally to a lower value. I never did that anti-chuffing MOD, but that MOD for the 'lil knobs sounds like a nice idea for the fat fingers. Also, back in the early 1990's, I've heard of other AST-803A / DX-440 users that have monitored Gulf War COMM's from 25MHz - 30MHz with just that radio's 40 inch telescopic whip. Find a portable that has that today. Ya know what, there are still Yahoo Groups on the Sony ICF-2010 portable, but I still don't think that there's a Yahoo Group for the ATS-803A / DX-440. Hmmmmmmmmmm... Maybe we should start one, since it sounds like there's enough fanfare and info to do just that.

For LW, MW, and lower HF, a homebrew Windom antenna with a 4:1 W2DU current Balun. But for FM, I mostly use the telescopic built-in whip antenna. One EXT modification that I did with EXT Antennas for that radio was to make a plug with opposing 1N4148 diodes across the center and GND conductors, for decent spike protection. Where I'd gotten that idea from were the Sony ICF-2010 portable gurus that did that to protect that radio's static sensitive J-FET front-end. BTW, that is interesting that your ATS-803A doesn't seem to like +9VDC going to it. I'm not using the original wallwart for my radio, but one from a trashed cordless phone base unit that is a transformered wallwart that happened to be +9VDC, 500mA, loaded. So, that worked out fine. BTW also, you might be able to find such one yourself at any junk store, or the Salvation Army, or Good Will, stores. I'm buying up every transformered wallwart I see, most for around $1.00 each. You just never know what they might be useful for. Better than +$20.00 for a new one.

Do you want to download the Service Manual for that? Here's the link for that here,     https://elektrotanya.com/realistic_dx-440.pdf/download.html
As for your ATS-803A not liking 9VDC? Are you using a transformered AC to DC wallwart, or a lite-weight switching one? That will certainly make the difference in noise. However, if yours is a happy camper at 6VDC, sounds like you are good. One thing weird about this portable is the write-up review that it had gotten in Passport To World Band Radio. This is the only radio where under 'CONS' they've listed NONE. That was very strange, since they would usually rip into every idiosyncrasies that a radio has, no matter how minute that is. Look under the Passport To World Band Radio reviews from 1990 - 1992. 

I've told Ray Jay about this portable for years, and apparently I'm not the only one,    https://radiojayallen.com/realistic-dx-440-sangean-ats-803a-am-lw-sw-fm-radio/

I still use mine daily, or should I say nightly, as a bedside radio. Radio Jay did knock the selectivity on the FM portion of this portable. In the mid-1990's, I did the Bruce Elving IF TOKO filter swap, from 200kHz to 110kHz, and after that it was, and still is, an FM DX machine. Necessary today with all of those FM translators littered, (And yes, I mean littered.), all over the FM dial. My big gripes are the same as with other portables. When either the memory AA batteries, or the "D" batteries, leaked, that acid would run into the main board. I run my portable off of a transformered wallwart. No battery acid, and no RF hash from a switching power supply. Of coarse, when I loose power at the house, I have to reset the clock and the 9 Memories on it. (B.F.D...) The other pitfall is that ribbon cable that loosely plugs-in to a terminal strip are dissimiliar metals, thus corrosion always seems to happen on the pins of that cable. I've repaired several ATS-803A's / DX-440's by hard soldering those ribbon cable pins to the board. Problem solved, and mine still working +27 years later of having that done. Anyway, +30 years later, my Sangean ATS-803A still rocks on.   

What do you have for a good Independent Earth Ground? A decent Ground cable / rod, connected to your receiver's chassis, can improve MW rejection to, even a single conversion, receiver, when DX'ing the SW bands. Especially a double and triple conversion receiver. Then, to improve Ground soil conductivity, water the area where the Ground rod is pounded into. And BTW, a good Earth Ground can also improve your receiver's sensitivity from LF to about 15Mhz.   

Спасибо! Now, if that's not an incentive to get my RTL-SDR radio up and running, then nothing will. This is certainly the other way to view Meteor Scatter, when you can not see the meteors due to cloud cover. Still, hearing scatter reflections on a vehicle's FM radio is a neat way to kill drive time. Did you also do the SDR waterfall from 25MHz - 30MHz? That should be interesting to view during Meteor Scatter.

Huh... Radio Jay Allen covers the Tecsun S-2000,     https://radiojayallen.com/grundig-satellit-750tecsun-s-2000-another-look/
His reports and descriptions are quite layman's terms, (Which can be good and bad. Good for 95% of the populous, but bad for us that want tech specs.), but it is a look at another opinion on that portable.

Quick searches for USA FM / AM / TV / LPFM / TIS Stations from the FCC:

 FM Query     https://www.fcc.gov/media/radio/fm-query

 AM Query     https://www.fcc.gov/media/radio/am-query

 TV Query      https://www.fcc.gov/media/television/tv-query

 LPFM Search      https://www.fcc.gov/media/radio/lpfm

 TIS Search          https://www.fcc.gov/media/radio/travelers-information-stations-search 

Then, this commercial site is also very useful:        https://radio-locator.com/

There. Bookmark these, and thar' ya is.

TV DX Loggings / Re: Television Repack and Digital TV
« on: August 10, 2020, 0421 UTC »
Do you still have a VHF beam antenna, or even a beam for FM fringe reception? If so, point that at Clarksburg, WV and see if you can get WDTV VHF CH5 on a TV rescan. https://en.wikipedia.org/wiki/WDTV     One of the very few VHF Low Band TV channel, that is 8VSB, to be there. The question is, for how long? Too bad about the old Clearfield, PA analog WPSX-TV CH3. They lost a lot of range since the analog to digital transition and use to have viewership in WNY. Can you RX whatever their digital UHF channel is?  https://en.wikipedia.org/wiki/WPSU-TV

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