HFU HF Underground
Technical Topics => Equipment => Topic started by: redhat on February 14, 2015, 1944 UTC
-
Just curious if anyone has any production receivers that can go to 1720 or better. I have a Sony SRF-59 AM/FM walkman that goes at least to 1750 KHz, and you can pick them up online for under $20. MW DX people like them for "ultralight" DX, and I would get a real kick out of someone listening to us with one in the future. Sadly, my Ratshack TMS-152 C-QUAM receiver was never expanded band, but I'm sure it could be pushed up there, and my Carver's all stop at 1710.
Any other RX's come to mind?
+-RH
-
Not counting SDR & HAM rigs, my Panasonic R5000A does, quite a sensitive receiver. I also have a PL-660 on order for those trips away from home. Many of the pre-WWII Hollow State rigs receive this portion. I did quite a bit of 1710 DXing using a restored Philco 650B Tombstone set. Worked very well! (have a few vids on my channel showing this). Seems many portables from the 60s 70s and 80s lack this portion of the band, though obvious exceptions exist. Zenith T-O's in the Royal 7000 series and later get this portion. I believe many of the Rat Shack higher end portables and DX series receivers do also.
-
8) Do you have 2nd. hand stores where you live? 8)
-
Not sure how high some of the radios go, as usually all I hear is static just above 1700. I think the SRIII will tune as high as 1720, I'm pretty sure the Sony ICF-38 portable tunes that high also. My Sony SRF-59 probably tunes that high, also.
A lot of SW digital portables will tune that portion of the band, but using their SW circuits, not their MW circuits, which can be a negative, even if the SW circuits have extra RF amplification. I think this is because of the MW band stop filters in a lot of radios' SW circuits. But that's just a guess.
-
According to the test procedure for the SRF-59, you are supposed to verify that coverage runs from 500-1750 KHz. I imagine this is fairly typical of dial tuned analog radios. I wonder if the CC Radio EP does this as well?
Yes we have thrift stores here, I thought Everytown, USA had one :)
+-RH
-
I have a Sony SRF-42 FM stereo/AM stereo walkman that goes up to 1750 kHz and a GE SuperRadio III (7-2887B) that goes way up to ~1775 kHz.
The rest of the ones that do get to 1720 are amateur rigs or SW rcvrs. Of the radio that are regular consumer models either stop at 1600 (tube, old transistor) or right at 1710.
-
The Sony ICF-2010 tunes continuously past 1700 and I've picked up weak MW stations on 1710. Not sure whether the internal ferrite antenna for MW is cut off internally past 1710, I'll have to check after dark or early in the morning to see how high it goes.
The Palstar R30 series excel at MW -- bulletproof front end -- but there's no built in antenna. So far I've tried only my homebrewed loops for LW, MW and some HF. Pricey for MW, though, considering how few interesting AM stations are left in the U.S. If I lived closer to the coast I might invest in a better MW loop.
Update: I checked all my receivers. No-go on the Sony ICF-2010 with the internal ferrite antenna. It diverts to the whip. And it's not easy to isolate the built-in antennas by plugging an external antenna into the jack.
So my best extended MW receiver is the Palstar. But it is pricey for that.
-
Sony ICF 7600GR tunes trough 1710 KHz. Before 1710 it uses MW receiver, and after 1710, uses the SW receiver. As say BoomboxDX, the result is negative. It's most notable when band noise floor are high. Before 1710 noise is constant, after, it changes to more silent noise.
The Sangean ATS505 goes up to 1705 with the MW receiver, but seems that after 1710 or more up has more sensitivity than the Sony. I received some station in argentinian x-band in 1710 with equal quality than the MW receiver segment.
-
For whatever it's worth my Sangean PR-D5 tunes as high as 1710. Probably the other radios in that series (PR-D15, PR-D7, etc.) stop at 1710 also.
-
A lot of mass market Discman type CD players produced over the last two decades had digital tuning in the radio section. Several I've ran across tune up to 1750 kHz. The Kaito/Tecsun 200 AM loop works well with these things as it tunes a bit high.
I've had a few of the players. Considering the small ferrite bar in the player and so-so pll, they do a decent job when inductively coupled with a loop.
You could probably pick up a player for a buck or under at a yard sale. The above loop goes for about 20 dollars, or you could roll your own using the tuning cap from busted portable radio, magnet wire, and some pvc tubing. The latter ought to come in at or slightly above 5 bucks including the player.
BTW, if you need a knob for the tuning cap, there's a guy on this board that can help you out. He's a knob crazed fool.
-
A lot of portable digital SW receivers built before, say 1996, tune as a shortwave receiver from 1630 khz up. If it's one with a good front end such as a Sony 2010 or the RS DX 440 you can run a serious directional longwire into them.
-
The problem with some of those receivers (the DX-390 is one of them) is the 1620-1800 section of the SW 'band' is relatively insensitive. I think it may have something to do with the bandpass filter (or is it a bandstop filter?) put in the SW chain to reduce AM band local interference.
-
Both the Tecsun PL-660 and PL-880 can be tricked into that range by using the shortwave up/down button that selects the band. Toggle down until you reach the 120 meter band range. The 660 renders the lower band edge at 2245 KHz and the 880 renders it at 2300 KHz. From there one can manually tune down to 1710 with the tuning knob. I have no idea what the sensitivity is like but my 660 has a weak birdie at 1910.