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Author Topic: Best ham transceiver for MW reception?  (Read 93571 times)
K0OD
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« Reply #15 on: February 13, 2015, 09:12:51 AM »

Don't know what specs you're referring to. I doubt they provide meaningful numbers about MW receiver performance amid  high power broadcasters using 1,000 foot towers (or QRM in a ham band during a contest). Specs you see in connection with entry level receivers are often written by marketing people.

I recommend that you read up on the equipment used by the most successful 160 meter contesters. I'd also assume those old  Kenwood engineers knew more than a brand new General. Low band DX reception is mostly about REJECTING bad stuff. That's not an intuitive piece of info, but by the time you've won some low band DX contests, as I have, you'll understand.

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AD4U
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« Reply #16 on: February 13, 2015, 02:59:14 PM »

In my 50+ years hamming and MW and SW listening I have used many many rigs such as Kenwood 930S, 440S, ICOM R-71A, ICOM 7000 transceiver, and even an ICOM IC 9000 receiver. NONE of them even comes remotely close to the R-390A for performance in the US AM broadcast band.  NONE!

Dick AD4U
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KD8UEI
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« Reply #17 on: February 13, 2015, 07:39:36 PM »

Don't know what specs you're referring to. I doubt they provide meaningful numbers about MW receiver performance amid  high power broadcasters using 1,000 foot towers (or QRM in a ham band during a contest). Specs you see in connection with entry level receivers are often written by marketing people.

I recommend that you read up on the equipment used by the most successful 160 meter contesters. I'd also assume those old  Kenwood engineers knew more than a brand new General. Low band DX reception is mostly about REJECTING bad stuff. That's not an intuitive piece of info, but by the time you've won some low band DX contests, as I have, you'll understand.

I would say that rejecting the bad stuff is desired on all bands, not just the lower bands. To help you understand where I'm coming from, I don't intend to DX on 160 m. I don't have the space for 160 m antennas. I'll be lucky to put up an 80 m antenna and even then it will be far from resonant. I'm also not into contesting. Maybe that will change in the future, I don't know, but for now I intend to be a casual user who occasionally does some DX when the bands are open and clear (i.e. not when a contest is running). My primary interest is studying propagation.

As for MW DXing, the ability to receive on the AM broadcast band is more important to me than having 160 m.

I have found that the attenuator in the Kenwood TS-480SAT can be turned off by changing a couple of jumpers. This is given in Kenwood's extended manual; it's not a "golden screwdriver" mod. So as it stands right now, it looks like the Kenwood is the way to go. I just never cared for the two-piece design.


EDIT: I want to be clear: I have never doubted the engineers. I know exactly why they put the attenuator in the radios. My question is which of the transceivers is best for MW DXing. I'm not questioning the design of these radios for amateur use. That's why this question is in the SWL section.
« Last Edit: February 13, 2015, 07:53:56 PM by KD8UEI » Logged
K0OD
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« Reply #18 on: February 13, 2015, 10:57:38 PM »

Well, 160 nearly touches our AM broadcast band. Similar propagation. Similar obstacles. You'd be best to browse the web's many 160-meter resources. Top Band ops tend to be technically savvy fanatics often with no-compromise equipment and colossal antennas. My own experience is more on 40, 60 and 80.

The R-390A mentioned by AD4U was a military receiver made 50 years ago, a true "boat anchor" weighing about 85 lbs, and employing 26 vacuum tubes. I'm sure they're very resistant to overload. But certainly not for everyone, including me.
http://en.wikipedia.org/wiki/R-390A

GL
 
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K0YQ
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« Reply #19 on: February 14, 2015, 07:24:03 AM »

Not going to jump into the receiver debate.  I also like to casually MW DX and my old Drake R7 serves the function well.  I also can't put up anything like a beverage or pennant outside, so I built a 4' diameter box loop tuned with an old air variable cap.  It sits inside, and does a shockingly good job when peaked and rotated.

GL and have fun.
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K0OD
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« Reply #20 on: February 14, 2015, 07:34:49 AM »

Hey, how about a page from long ago... a car radio?
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AD4U
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« Reply #21 on: February 14, 2015, 09:07:41 AM »

Well, 160 nearly touches our AM broadcast band. Similar propagation. Similar obstacles. You'd be best to browse the web's many 160-meter resources. Top Band ops tend to be technically savvy fanatics often with no-compromise equipment and colossal antennas. My own experience is more on 40, 60 and 80.

The R-390A mentioned by AD4U was a military receiver made 50 years ago, a true "boat anchor" weighing about 85 lbs, and employing 26 vacuum tubes. I'm sure they're very resistant to overload. But certainly not for everyone, including me.
http://en.wikipedia.org/wiki/R-390A

GL
 

I was very fortunate to be given a true Collins R-390A receiver by a good friend Vic K4IVK when he had to go into assisted living after his wife of 60+ years K4IVG (I'm Vic's Girl) died. I thought the R-390A worked quite well but since I got the receiver for free, I decided to spend some money and have it restored electronically and cosmetically.

Off it went to Chuck Rippel in Norfolk VA. Chuck tore it completely down, removed all the hardened grease from the gear train, cleaned, oiled, recapped and repaired and aligned it to new condition. During the restoration process Chuck kept me informed of his progress. He made several suggestions to improve the receiver's performance, which I OK'ed. After about 12 weeks on Chuck's bench I have a R-390A that works just as well as (or better than) a new one did many years ago.

Being fortunate to own a $12,000 (I did not pay that much for it) ICOM IC-9000 receiver, I put it and the R-390A side by side. Using my 160M dipole as an antenna and in the AM broadcast band (0.55-1700 KHz) the R-390A absolutely blows the $12,000 ICOM IC-9000 away. This is one test that is definitely night vs day.

One reason the R-390A performs so well is ALL the critical circuits in the R-390A are ganged together and "track" together as the tuning knob is moved. As far as I know no other receiver, regardless of cost, does this. In its day the R-390A was designed to be the best receiver no matter what the cost. IMO it fills that bill even today.

The R-390A is another of Art Collin's master pieces.

Dick AD4U
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K0OD
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« Reply #22 on: February 15, 2015, 09:25:16 AM »

Quote
"I put it and the R-390A side by side. Using my 160M dipole as an antenna and in the AM broadcast band (0.55-1700 KHz) the R-390A absolutely blows the $12,000 ICOM IC-9000 away. This is one test that is definitely night vs day."

Blows away?  Day and night?  

That endorsement reminds me of too many EHam reviews. Precisely how is the "day/night" benefit of the R-390A manifested in terms of listening or DXing?  I have several nice AM radios including a 1977 Panasonic RF-2200 portable which has a cult following among BCLs. Frankly my old TS-850 sounds a bit better with its built-in speaker on broadcast band A/B tests. All my many MW-capable radios including a 1937 Zenith 5-tube desktop hear DX equally. No doubt the Collins is better amid crushing RF levels. But most of us aren't listening to AM from a battleship in the center of a fleet in wartime.  

At night, with many stations coming in on each AM channel, I don't understand how one AM radio can be much better than another.    

I'd love to see a demo on Youtube of your findings.    
« Last Edit: February 15, 2015, 09:29:55 AM by K0OD » Logged
AD4U
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« Reply #23 on: February 16, 2015, 06:40:32 AM »

I am not into youtube but I did a simple test Sunday 2/15/2015 starting at 2:30PM EST.

First I connected the R-390A to my 160M dipole which is about 80 feet high between pine trees. Starting at 530 KHz and slowly tuning up to 1720 KHz I was able to copy 71 stations on the AM BCB using the R-390A. That is not a misprint. I copied 71 AM BCB stations on the R-390A. While not every station was 5/9 or arm chair copy each and every one could be heard well enough to make out what was being broadcast.

I am located in central SC. While I did not remain on each and every frequency long enough to ID each and every station, I am certain that I was able to copy AM BCB stations in SC, GA, and NC during mid-afternoon.

Then I connected the ICOM R-9000 receiver to the same 160M dipole. The time was 3:10 PM EST. Carefully tuning from 530 KHz to 1720 KHz I was able to copy 18 stations in the AM BCB well enough to make out what was being said.

I have a rather extensive test bench which I have used to restore some 40 boat anchor HAM rigs in my collection and some 50 AM BCB and SW receivers from the 1930's to the 1970's.   I tested the R-390A and the ICOM R-9000 and in the AM BCB, I can detect a 0.1uV signal on each receiver, when using the BFO and / or the CW mode. I did not try to make any S/N measurements.

My conclusion is that, even though both receivers compare equally when using a signal generator, ON THE AIR the R-390A is quieter in the real world and has superior rejection of adjacent signals, images, overload, etc etc than the (my) ICOM R-9000.

When using the ICOM R-9000 there seemed to be significantly more "noise" that masked many of the weaker desired signals on the AM BCB. I have no idea if the noise was internally generated phase noise, external noise, or possibly some kind of overload or image or mixing.

I live in the middle of a 700 acre farm so power line hash is not an issue. The nearest AM BC station is about 6 miles away and runs 5000 watts om 710 KHz in the daytime. This station was on the air when these tests were run. I seriously doubt if the noise heard on the ICOM R-9000 was over load from this station but I guess that is possible.

But for whatever reason, "noise" masked many of the weaker AM BCB signals on the ICOM R-9000 that were perfectly readable on the R-390A. I will leave it at that. If anyone wishes to visit my shack and witness the same demonstration, I will be glad to host.

Dick AD4U

PS: At anytime during mid-day when AM BCB propagation is at its worst, when using the R-390A I can listen to WSB 750 KHz in Atlanta some 250 miles away "arm chair copy".  If using the ICOM R-9000 I do not even know WSB is on the air.
« Last Edit: February 16, 2015, 07:37:42 AM by AD4U » Logged
K0OD
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« Reply #24 on: February 16, 2015, 08:46:29 AM »

71 stations compared with 18 is impressive, to say the least.

So why doesn't every Top Band contester/DXer use an R390a or similar? (I understand that "cranking" one all weekend isn't to be desired). Why hasn't the military gone back to such radios? (maybe they have... secretly?)  Maybe the AM BCB is the R390a's sweetspot. Or maybe your R-9000 sucks on the BCB? Try another receiver.

My only tube receivers are two keepsake 1930s Zeniths. Last time I used a similar radio to yours was my Collins 75A2 which was certainly an upgrade for my station in 1960. But short of miraculous.  I understand that the  ham 75A2 was hardly in the class with your military receiver.

I'd like to hear what some boat anchor/low band fanatics have to say. 
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RENTON481
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« Reply #25 on: February 17, 2015, 02:40:23 AM »

I'd be curious as to how a R390A compares to the Drake R8, which is one of the more recent MW DX tabletop receivers that seems to get the biggest reviews.

I remember a few of the top MW DXers in the 70's and early 80's used R390's, along with Drake SPR4's.
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W2JUV
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« Reply #26 on: February 17, 2015, 07:07:31 AM »

I've owned a few Icom HF rigs and none were great on the AM broadcast band.  Agree with two earlier posts:

1. A GE Superradio with desktop loop antenna works great for AM Dx.
2. An old car radio...Yes! Years ago I used a mid-70's Delco radio with a short wire antenna.  Worked very well.
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KC2QYM
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« Reply #27 on: February 17, 2015, 12:45:25 PM »

A also have an old GE superradio that I picked up at my town's recycling center.  It was dusty and had some paint splattered on the case but it worked great when I got it home.  The secret of this radio is the double ferrite bar antenna.  On the the top floor of my woodframe house I was amazed at the radio's capabilities.  I have no specs and only use my ears to make the determination that this 'dumpster diver' find was worth every penny I didn't pay for it.
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K5TED
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« Reply #28 on: February 17, 2015, 08:33:40 PM »

It's all about the antenna. Shielded loop is good, or even a typical plastic frame AM wire loop antenna that comes with most AV or stereo receivers, if you have one of these to place near it..
http://www.sarmento.eng.br/Loop_Ferrite_Rod_Antenna.htm

Very easy to build and fits anywhere. The ability to orient it to either enhance or null a station is invaluable.

The (large) tunable ferrite loopstick is probably the most useful tool in a MW DX toolbag.

Don't waste time with the cheap 'Kaito' loop antenna. You can build a better device out of an old tabletop AM chassis loopstick and a variable cap.

I mostly use a Belar LP1 with Wideband mod and preamp for MW.

LW is tough here in S. Texas, at least here in town.
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RENTON481
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« Reply #29 on: February 17, 2015, 08:52:49 PM »

A also have an old GE superradio that I picked up at my town's recycling center.  It was dusty and had some paint splattered on the case but it worked great when I got it home.  The secret of this radio is the double ferrite bar antenna.  On the the top floor of my woodframe house I was amazed at the radio's capabilities.  I have no specs and only use my ears to make the determination that this 'dumpster diver' find was worth every penny I didn't pay for it.

The GE Superadio doesn't have a double ferrite antenna.

There is just a single ferrite loopstick inside, but it's 200 mm (which makes a big difference), and has one long winding (which may or may not make any difference....). It also has an RF amp transistor and a hot IF chip -- which help to make a Superadio such a good radio.
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