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Communications Receiver Advice

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Corbin, KY
#21
PS. The "desktop" portables come with decent antenna jacks and have extra electronics that can withstand the signal of a full-size outdoor antenna. Some "portables" can use an external antenna but you need to be careful since they can overload the portable receiver -- and in rare cases, damage the portable.
With this said I would not discount an Eton E1. Sure, QC can be hit and miss, but if you were to get a good one they are surely a keeper. I had one for a bit, sold it though to get my R75. The R75 has more "tools" and computer control is nice, I would however pit the R75 against the Eton and that would be a tight race (with the Eton having a slight edge in broadcast listening (but nothing a little ECSS can't fix on the R75)). Both are very good rigs.

I have owned the R-5000 for some time. Good radio! But I feel the Eton and the R75 have one up on it. Since the R-1000 is the little brother, I would not be that impressed. Of course the Kenwood was a decent rig, just lacks some of the features of the other two.

The stock filters on the E1 are great. While the R-5000 always made me wish for more filters, the E1 had me wishing for nothing. The PBT on a semi portable was a Godsend. The R-5000 of course has I.F shift (same as a PBT) but the filters left me wanting.

Now with all this said, I would save some more money and buy an R75. For utility and SSB use nothing will beat it in the price range. Sure some SDR receivers can claim the see all click to tune all title, I would place my bets on the R75 with a knob any day. YMMV!
 
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#23
I have already tried a DX-394 and had a bad experience with it so I am heasitant to try another one. I would love to try an Icom R-75 but it is a little too expensive for my budget.
If you can pop for $450, take a look at the current Alinco DX-R8T communications receiver. I have one, as well as an R75. I wrote up a review in the review forum if you want to look it over.

But before spending any money, what was your bad experience with the 394? It may be something that just getting a new receiver won't fix, and more of an antenna / noise issue possibly.

That being said, what makes the DX-R8T somewhat at the inexpensive end from an amateur radio standpoint specification wise, makes it a fine BCL / SWL receiver in it's price range.

For narrow AM filtering, the trick is to use SSB, (either upper or lower take your pick), and the 2.4khz ceramic filter is inline. Fortunately, this slope of the filter isn't razor-sharp, so fidelity is preserved. If you try to listen to AM with the narrow filter switched in, it doesn't sound very good, but put it into SSB, take your pick of sideband, and bingo. Quality narrow filtering with good fidelity. Guess what - you can take it even further for super narrow for am and it is still acceptable for hard core dxing. The narrow filter is actually a ceramic 1khz type, but again, the slope is wide enough to make it very handy for bcb / swl dxing when using ssb for am on purpose. You can still select your choice of slow/fast agc.

Can I do the same thing on my R75? You bet, even though I have it populated with 3rd party filters that pushed it beyond the $1k range. Either receivers audio is mere utilitarian with the front-panel speakers, so plan on getting a good speaker. It might be like getting a whole new receiver. :)

Fortunately, the dial-knob is very slow, and the receiver is steady enough that doing narrow am filtering this way isn't some sort of twitchy little trick. You just have to dead-on frequency and stable to sound good, and that's no problem with this radio.

For some, the ergonomics may not be ideal, but I got over that pretty quickly and just applied the gentle touch to it. Oh, and if you want to get your feet wet with SDR, it has an output for that too, although not the level of kilobuck-sdr receivers.

While it lacks an effective noise-blanker, or any sort of advanced notch or beat-cancelling, (IF shift works ok, but keep it centered for swl'ing) I've found that in the long run, fixing the noise, or using a directional antenna to be the better long-term solution than heavy digital signal processing.

While I have nothing against older receivers that work, the modern Alinco DX-R8T is worthy of consideration.
 
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#25
If you go putting new caps in a radio and the tolerance of the components after the new cap are older and not up to the specs they at one time were, you may do more harm then good.
In most cases, it's electrolytic capacitors that go faulty, mainly due to heat in confined spaces. Electrolytic capacitors are used in the power supply and audio stages, not in the frequency determining RF and IF stages. The problem with those capacitors in the power supply is they dry out and then you start to hear some hum maybe. Also they can go short circuit and the collateral damage can be quite severe, taking out diode bridges and even the main power transformer. With modern radios getting smaller there is greater heat build-up inside the case and stacking radios in a cabinet makes matters worse. Big old radios stay cooler longer! I have a big ole' JRC NRD515 getting on for 30years old that's as good as new, my Yaesu VR5000 runs hot as hell and is packing up fast.

By the nature of their construction and the applied voltage, electrolytic capacitors have a very wide tolerance. Old 'wet' types in early radio's were +100/-50%! If you replace an electrolytic cap, then as long as you are close to the original value and the same or slightly more operating voltage there should be no problem. Don't forget they are polarised - you have to get them round the right way and sometimes the markings are pretty vague.
 
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#26
Thanks!

I decided to go for an R-71 and found a good looking one ebay. It came with the replacement ram board (Not installed, still is running on original board) and a power supply for running it off of 13.8v, which I believe should keep it from heating up too much. So far I have seen none of the probems that the Dx-394 had. There is occasionally a really bad buzzing noise that drives me insane. I know it is coming from my house somewhere, but I still haven't found it. It happens on my other portable radio too. So far it is pretty good on am, but the ssb is amazing. With the passband tuning the signals are as clear as a bell. I look forward to having this great radio.

Thanks again for all of the help!
 
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#27
Sounds like a beauty:) I hope you have all the luck as I've had with mine. It's been a faithful workhorse and I am very happy with it. I myself look forward to reading some good stuff about yours.
 

ratboy

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#30
I just got an R71A, cheap, $275+shipping, and somehow it survived the trip from the West coast to Ohio without any problems, even though it was VERY badly packed, just sliding around on top of some steel antenna brackets. Worked great right out of the box, the only real problem was cross threaded case screw that my screwdriver tore up when I tried to get it out. It's dead on freq on LSB and about 30hz high on USB, not enough to worry about I had to cut a slot in it with my Dremel tool and finally got it out. As usual, several of the other case screws are messed up and I will be ordering some from Icom so it looks good.
 
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#31
RB glad you got one too:) yeah I swear the screws on this rig-it's like they are made from solder they're so soft! I know with mine I had to massage c78 back/forth a few turns as it tended to drift up in usb a bit. Hasn't done it since:)
 
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upstate new york <utica>
#32
Dude you wont go bad with a kenwood R5000
ive had mine for years 7 years & it siezzed up on me & A guy told me spray WD-40 in the VFO
& I thought he was CRAZY
it worked for me 100%
& If its out there I can7
hear it on my 4wall bedroom antt... hay man it works
hoped I helped you

And I dont work for kenwood
allso I like icom back in the day I like real S reading s
Chow-------------------------------------Chow
 
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#33
What you get in a "communications" receiver is intelligibility of received voice and CW signals - no "communications" receiver should be designed to have Hi-Fi sound - you can buy a cheap broadcast receiver to do that. Yes, I know lots of guys feed the line level output from their receiver through an amplifier and full-range speakers and it does make it sound "better" but it won't do anything for winkling out those weak and noisy signals in a crowded 49m band in the wee small hours - good headphones, a narrow filter, an accurate digital display, a noise blanker and a RF gain control are worth their weight in gold - and a pair of Mark 1 well trained ears are the most useful accessory!
 

ratboy

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#35
RB glad you got one too:) yeah I swear the screws on this rig-it's like they are made from solder they're so soft! I know with mine I had to massage c78 back/forth a few turns as it tended to drift up in usb a bit. Hasn't done it since:)
Those screws really have caused me problems over the years, I've had several R71as, an R7000(really miss it) and an R7100, all used, and all of them had at least one messed up screw on them. My present R71a looks like it's been recapped at least on the display side. I haven't checked to see if the battery looks original, or if the board has been replaced with one of the new ones that don't die with the battery. The worst one I ever had had all kinds of mods done, filters, recapped, etc. It had some intermittent issue (I knew t when I bought it, but I never could find it) where the audio cut out randomly. I finally gave up on it and put it up on Ebay, where went, even with the problem, for far more than I paid for it.
 
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Columbia, SC
#37
I am looking into purchasing a desktop communications receiver for general SWL and some SSB. My price range is around $300-$400.
I'm going to buck the trend and probably tick off a few hams here. If that is what you want, all your want, the Tescun 660 will do those things as well as any radio in the world with the same antenna. Don't know why people keep trying to talk people into getting more expensive radios.
 

SCPD

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#38
Having two portable radios, PL660 and Satelitt 750, what all who have the experience and knowledge that post here, they are 100% on target as antennas. Do the research here or elsewhere, yes ,you can get a nice desktop which I am looking at but I am also looking at my antenna options as well.
 

Token

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#39
I'm going to buck the trend and probably tick off a few hams here. If that is what you want, all your want, the Tescun 660 will do those things as well as any radio in the world with the same antenna. Don't know why people keep trying to talk people into getting more expensive radios.
“Don't know why people keep trying to talk people into getting more expensive radios “? Probably because those more expensive radios will perform better under many conditions. Oh yes, and the OP specifically asked about desktop communications receivers, not about portables, a desktop the OP ended up getting for the very bottom end of his stated budget. And what do hams have to do with it? Several responders here are not hams at all, just avid listeners.

If your only technical criteria is only sensitivity, if you are not going to use an external antenna, if you are always going to receive stations that are not closely spaced with other stations, and if you are looking for a “casual” SWL radio, then the 660 will perform almost as well as many of the communications receivers that have been discussed in this thread.

The Tecsun 660 will not receive SWL BC and SSB transmissions “as well as any radio in the world”. It will receive those signals as well as many radios under some specific conditions, but the more trying the conditions the less well it will compare. For armchair reception of high power or in-the-clear stations it is one of the better low cost choices out there, but not when the going gets tough.

The R71 the OP ended up getting, a radio that matched his stated desire for a desktop radio and fit his budget, is more than twice as sensitive as the Tecsun 660 (the Tecsun manual suggest the R71, at 0.2 microVolt for 10 dB SNR, is about 4 or 5 times as sensitive as the 660, at “less than 1 milliVolt” according to the manual here http://www.radiomanual.info/schemi/RX/TECSUN_PL-660_user.pdf ). The selectivity of the R71 is on the order of 20 to 40 dB better, at the same width, than the 660, this is 100 (20dB) to 10000 (40dB) times better. The R71 has far better dynamic range, it has a lower noise floor, and it has better LO phase noise. All of those features mean that, all other things being equal, the R71 will continue to perform well after the 660 has run into its limitations.

There is nothing wrong with portables, they are great for light or on the go DXing. They have their applications, applications for which a desktop is unsuited. But the user needs to not be blind to the limitations and problems of each individual unit.

T!
 
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ratboy

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#40
Having started out with going the cheap route, I can say that doing it that way is a mistake, a waste of money in so many ways. Before the net came into it, you had to try to sell your mistakes at hamfests, etc, but now it's not so bad, you won't lose your butt on a bad buy, you might get lucky and make some small profit. Buying a used receiver like an Icom R71A or similar for $350-400 is a better deal than buying a new Chinese portable, or an old Japanese one, IMHO. There is always a risk in buying something 20+ years old, but in my experience, if it works a day, it's likely to work for years without significant issues. My Kenwood TS-850SAT being the exception, where a couple of caps failed about three days after I got it. I don't blame the seller, it just happened, there's no way to fake bad caps being good. Luckily for me, my new, incredibly cheap vacuum desoldering station that I just got came in very handy (I cannot tell you how useful this thing is for working on stuff! Look on ebay and wait, you CAN get one cheap, if you wait for the right auction, mine was $269 new, and I got it for $25 including shipping!!), and I replaced a bunch of caps and the back up battery (In a socket and not soldered in) and it's working fine a couple of years later.
 
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