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Author Topic: FTdx-101D Tops Sherwood Chart  (Read 7283 times)
AC7CW
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Posts: 1358




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« Reply #90 on: May 16, 2019, 02:53:31 PM »

I'm wondering how narrow space dynamic range relates to total noise in the passband... DSP may be just finding strong signals at the edge of the passband center and removing them or it might be working on the overall noise in the passband. The former won't do much with regard to noise fatigue when not in a qso but the latter might, no?
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Novice 1958, 20WPM Extra now... (and get off my lawn)
K6BRN
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Posts: 1354




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« Reply #91 on: May 17, 2019, 01:57:36 PM »

I've designed and led the desigh teams for MANY digital signal processing systems. So, Having looked inside quite a few contemporary radios, here are my thoughts...

1.  Icom IC-7300:  A DSP driven radio with compromises in all the right places, an elegantly designed user interfaces and at the right pricepoint for the performance and features it offers.  Those are the three characteristics that still make it one of the best values out there.  BTW - I don't own one (I'm a Yaesu "fanboy" BTW) but I've used one.  Hard NOT to like it.  Well done!  Guess I'm an Icom Fanboy, too.

2.  FlexRadio Flex-6600:  An excercise in engineering elegance.  It blends modular design with minimalist internal materials/shielding/isolation (cost optimization) and takes advantage of some VERY good digital signal processing design to yield excellent performance.  Not the simplest radio in existence, but definitely an enthusiasts radio with a LOT of usable features.  Well done!  I'm DEFINITELY a FlexRadio Fanboy.

3.  Yaesu FTDX-3000:  A very classic and relatively expensive RF chassis for both TX abd RX (lots of shielded compartments, custom cast aluminum chassis) married to a low-IF (just above audio) DSP processor with excellent firmware to provide very good performance.  Tough as nails TX section.  Menu designed by three different groups of 60's hippies on LSD, with bad memories.  Still, a pretty goof rig overall.  Yaesu does analog RX VERY well.  And since nobody has really complained about my TX signals, I guess IMD is, well, goo enough.  Like I said, I'm a Fanboy!

I just love good equipment with good engineering!

Brian - K6BRN
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N6YFM
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Posts: 832




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« Reply #92 on: May 18, 2019, 11:07:18 PM »

Hello, where did all the poster's go?   Did the Elecraft K4 announcement kill this thread?

Hey, I do NOT have Attention Deficit Dis....    
                                                                  Hey look, there goes a squirrel !

:-)
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M0GVZ
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Posts: 403




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« Reply #93 on: May 19, 2019, 02:05:07 PM »

I'll dump this in as a prospective future buyer:

Those of you who purchase a -101D, give us some feedback on how the receiver handles band noise (man-made EMI, RFI). As I'm typing this I see an S7 noise level on 40M, most of it being hash from sources external to the house. I'd love for a receiver to be able to reduce or eliminate this to the point where weak signals are readable once again.

The sad part about this is that any radio with two receivers could be capable of doing it, the SDR ones especially those doing diversity receive even more so by having a small antenna connected to the sub receiver then feeding that back into the main receiver chain 180 degrees out of phase. That's pretty much the way the MFJ1025/1026s work with them having additional controls on phase and amplitude.

BTW if you haven't tried one yet you may want to give a MFJ 1026 a go.
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KX2T
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« Reply #94 on: May 19, 2019, 05:24:33 PM »

I use a MFJ 1025 in my station as well, on 75 meters I have an S9 noise level during the bay and night as well which the MFJ bring it down to S3, also on 40m its about an S6 and with the MFJ its drought down to S1. At night on 75 somewhere around 10 pm a local home 400 feet away has a solar panel system that seem to go into a deep charge cycle then for a few hours till 2 am or soo, this produces an annoying noise level in which the MFJ only does slight changes on maybe 10db yet the NB on the 7610 makes it go simply away, My FTDX 3000 I had didn't even come close in noise elimination of this type yet the IC7300 and the 7610 did a dam good job.
 
                        The best receiver in the land doesn't buy you squat if the noise reduction doesn't work well in a suburban QTH! 
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N2DTS
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Posts: 967




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« Reply #95 on: May 19, 2019, 06:14:24 PM »

I looked at some video's of the new MFJ loop antenna, quite a dramatic noise reduction.
My dipoles are not bad, but my zero 5 vertical antenna picks up a LOT of noise.
I did find the 7300 noise blanker about the best I have had.
I think the Elad was also good.
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KX2T
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Posts: 1103




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« Reply #96 on: May 22, 2019, 11:31:56 AM »

I am moving south in a few weeks out of the NE area and to warmer southern climates, I find out what the noise level will be down in Florida, yes I know lightning will be an issue but I mean man made noise, I have looked into a RX loop but will still try the phasing MFJ 1025. The loop may be better with lightning static though but it pays to have them in your arsenal. On the low bands I might be able to get some brown jacketed RG6 coax and make some blog style beverages 200 to 300 feet long which may also help in certain directions but on both the 7300 I owned and the 7610 the noise blanker has been one of the best I have used with excellent results plus the noise reduction which does have a slight change in the upper high frequencies of the audio spectrum really reduces the back ground noise without any digital artifacts. I would like to see someone who owns both the FTDX101D and the IC7610 compare them side by side and write a report of there findings.
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AC7CW
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Posts: 1358




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« Reply #97 on: May 22, 2019, 02:19:52 PM »

Direct sampling is becoming an industry catch phrase. Yaesu talks of direct sampling of a 9MHz I.F. That is hardly more "direct" than sampling the low I.F. in a double conversion design. They might capture more spectrum at the 9MHz I.F. than a double conversion rig and make the bandscope seem like the rig was direct sampling, there's that. If there is a mixer between the antenna and the A to D it is not direct sampling. Maybe we can request that the industry adopt a term such as "Indirect Sampling" or "Post Conversion Direct Sampling" or "First I.F. Direct Sampling" to indicate a single conversion SDR rig Smiley
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Novice 1958, 20WPM Extra now... (and get off my lawn)
KX2T
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Posts: 1103




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« Reply #98 on: June 01, 2019, 02:40:37 PM »

On the full Sherwood test report the blocking spec was at 100Khz not 2Khz or 2.5 Khz were the 101 is around the same as all the other top line SDR rigs, only the Kenwood 890S  has the higher numbers up around 150 at 2Khz spacing. Nothing fancy there just the way Rob test in his lab and will wait for the more detailed ARRL lab numbers.
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