FTdx10 & IC-7300: SSB Weak Signal RX (Video #17 in this series)
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- čas přidán 3. 04. 2021
- My good friend Joel, KC4WZB, loaned me his brand new Yaesu FTdx10. When I say loaned, I mean he picked it up at Ham Radio Outlet and brought it straight to me, so I could unbox it and shoot a series of videos, exploring the capabilities of this latest offering from Yaesu.
This is the seventeenth video in a series of videos I will be producing to show the capabilities of the Yaesu FTdx10. In this video I show how to use the Manual Notch filter and Contour filter to deal with annoying heterodyne and QRN, while trying to pull out weak SSB signals. I also show how to use the Manual Notch filter on the IC-7300 to simulate the function of the Yaesu Contour filter.
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73, de N4HNH - Věda a technologie
These videos are amazing and I really think this is what we need to be showing new general class operators from the beginning. I have never seen such a clear set of videos on features and how they are used. Many thanks.
Thank you so much, Don! I appreciate hearing that. I just want us to get the most from whichever radio we happened to have.
73, de N4HNH
Dear OM, not only are you making great comparison between two radios but, the information and experience you are sharing is amazing. There is tons of learning one can get from your videos. Thank you!
Thank you for understanding my mission. There are plenty of CZcams channels where they show radios receiving, knobs being turned, and buttons pressed, with no explanation. I’m trying to teach operating techniques. I appreciate that you appreciate that. Welcome to my channel! You made my day.
73, de N4HNH
Thanks!!!! FTDX10 the winner!!
Great review!! You sure convinced me about just how GREAT the Dx10 is!! No comparison!! Thank you so very much!!
I’m glad you found the video helpful and informative.
73, Doug
Bought both of these radios so, i
magine my luck when I found you. Thanks
You’re very welcome! 73, de N4HNH
Thanks so much. 73
Very good yaesu FTdx10
Yes, the FTdx10 is very good. Thank you for your comment! 73, de N4HNH
nd setting changes on the DX10 that improve the tuner ?
Hi there. I see that both radios have a similar NB and NR. Saying that which of tbe 2 rigs will reclmend for DXi g. I currently have the FT 2000D and the Iclm 7600 but I want to try SDR. Thanks so much
Javier
TI2JS
For DX,? Definitely the FTdx10. The hybrid receiver plus DSP has propelled the FTdx10 to number 3 in the world for RMDR (selectivity). It is beaten only by the Flex 6700, at number 2, and the FTdx101D at number 1.
73, de N4HNH
Another great video. Could you explain exactly what the heterodyne sound is and what causes it?
Heterodyne happens as a result of two different frequencies beating against one another. That’s how a superheterodyne receiver works. I shot a video about that last year, breaking down the stages of a HF receiver.
If the two frequencies that beat against each another are within 20kHz of one another, the resulting difference frequency could fall into the frequency range of human hearing, which is 20 Hertz to 20,000 Hertz (aka 20kHz). As we get older we might not be able to hear up to 20kHz though. We might be able to hear to 15 or 16kHz.
But the heterodyne I’m hearing from time to time is anywhere from 1500 to 2600 Hertz, well within the audio spectrum of HF SSB.
The heterodyne could be many things. That’s why I dedicated an entire video to tracking down noise sources. One of my viewers found his neighbor’s plasma TV was producing noise that interfered with his reception. He has “loaned” the neighbor a LCD TV. Some noises are broadband like that. Some LED lights can create terrible noise. Wireless phone chargers and wall-wart power supplies too. But a heterodyne is usually caused by an oscillator somewhere in the vicinity. It could be a baby monitor.
73, de N4HNH
@@n4hnhradio thanks Doug for that very detailed explanation. I'll take a look at both videos you mentioned in your comment.
Germany is waving a hand! 73's de Uncle Günter
Hi Deutschland! I’ve been to your beautiful country. I married into a German family.
Thanks so much for saying hi!
73, de Doug
@@n4hnhradio Happy thursday Doug. I am glad you like germany and hopefully your new german family treats you well...
Hope to talk to you on air one day. 73's de Uncle Günter
Was the transmit on the ICOM lit up? Glad you to told us about the signal running across the scope. I was going to ask you about that. I was thinking it was something just happening at my QTH.
No. That TX LED on the 7300 is confusing. It stays there on RX. It just gets bright when you transmit. I think ICOM should have put a green RX LED for when it isn’t transmitting.
I think everyone gets that WX tracker or over-the-horizon radar blip from time to time. Search the Web for information about the Russian “woodpecker”, from the 1970s and 1980s. It was worse.
73, de N4HNH
@@n4hnhradio Yes. I just realized that. You would think I would know since I own one. But, I’ve been using my FTDX10 so much, I forget about the little differences between the two radios.
I hope I haven’t forgotten how to use my FTdx5000MP by the time I finish making these videos. I will be putting the FT-991A up against the Ftdx10 in the near future.
73, de N4HNH
@@n4hnhradio That will be interesting. The 991 was an option but I didn't want to wish I had spent the extra money and get a better radio. When I saw it was number 3, that helped make up my mind. Glad I bought the FTDX10. The other option was the FTDX 3000. Thanks for all of your insight. These videos are golden and will benefit others for many years to come. Thanks to Joel. Is there a radio he doesn't own?
Believe it or not, Joel went many years without buying a new HF radio. I did too. It took me nearly 20 years to buy a new HF radio. Joel is careful like me. When the 7300 craze started, I think that was his first base station purchase in a couple of decades. I could be wrong. But I think his other radios at the time were vintage Kenwood twins. The separate RX and TX combination.
I was using a Yaesu FT-920, since 1999. I had made some modifications to its roofing filters, so it was no slouch. When I finally decided to buy my dream rig, I started reading reviews and watching CZcams videos. I rarely found a video that would do much more than switch back and forth between the radios, not explaining any adjustments they made, and sometimes not even making any adjustments. I wanted to see how good the radios were at mitigating QRN, QRM, etc., plus ease of use, menu settings, and more. Therefore I bugged Ham Radio Outlet for 8 months, trying every radio they had hooked up for demonstration. After I finally made my choice they were happy. I then decided to start making the sort of videos I wish I could have found when I was researching.
So Joel recently upgraded to the FTdx101MP for home and this FTdx10 will go to his cabin. Before he sells the other radios he loaned them to me. In fact he has no radio at the cabin now. The FT-991A was there. He’s waiting until I finish the video series and the FTdx10 will be the new cabin radio. It makes good sense because the FTdx10 is practically a FTdx101 without simultaneous dual-receive and VC Tune.
Joel is a great friend to me and to amateur radio.
73, de N4HNH
As I understand it, a notch filter works by attenuating a thin slice of a desired band of audio (or generally speaking any band of frequencies of interest, be it audio or RF). So, for example, if there is a stray tone that affects 1980khz, you can set the filter there and it will essentially cut out that portion of what you’re hearing. So it doesn’t make sense that you would apply the notch filter to broadband white or pink noise and expect miraculous results. Essentially all you’re doing there is taking out a chunk of the white noise that resonates with the audio system (and your ears) in the most annoying way. The side effect of applying the notch filter when no apparent notch-sized disturbance exists is to notch out wanted signal, in essence, reducing the audio bandwidth, which reduces fidelity - similar to the way a BW filter would affect the signal. Please correct me if I’m wrong.
A notch filter attenuates the audible tone produced as a result of heterodyne, like someone tuning up near where you are tuned to, or something in your neighborhood that is mixing against the frequency you are tuned to. I have the latter situation when I’m tuned to 7.150MHz. The tone happens in the audio spectrum, otherwise you wouldn’t hear it.
The notch filter width can be set to wide, medium, or narrow. Wide and medium affect fidelity to a more noticeable degree. But the tone or noise could make someone unreadable. So, using the notch filter is a compromise. Fidelity is not the concern when you have a tone mixing in with the station you are trying to hear.
I keep my Yaesu notch filter set to narrow. It is very effective against heterodyne interference without affecting the audio fidelity much at all. The Yaesu has a separate, Contour filter, that can minimize atmospheric noise, when I’m trying to pull out a barely readable signal. The ICOM doesn’t have a Contour filter. The closest you can get to a Contour filter with the ICOM is to set the notch filter to wide and sweep it through the audio spectrum until you can pull out what the barely readable station is saying. Fidelity is not important in such a situation. These are techniques that are used only when necessary.
Rob Sherwood recommends that the IP+ on the IC-7300 be left off as it adds nothing to help receive performance. AB4OJ actually noted on the IC-7300 that he tested that the MDS was affected negatively by having it turned on. There was as much as 10 - 13 db degradation in AF noise with it on. He said that the effect increases below 40 meters. It does not perform the same function as on an older analog design. I’m curious to compare my FTDX-10 with my older IC-7300. Of course, it is a more expensive radio and I expect increased performance. The DNR on the Yaesu radios do seem to perform very well indeed.
IP+ employs analog to digital converter functions, called Dither and Random, to inject random noise at the input of the analog to digital converter. Believe it or not, injecting this noise can cause the ADC to work some magic that can improve the 3rd order intercept performance of the receiver. This dither technique adds to the noise floor, by approximately 9dB, decreasing sensitivity. But some laboratory tests indicated an improvement in the dynamic range of the receiver by as much as 13dB. So, think of it as trading 9dB of receiver sensitivity for a 13dB improvement in dynamic range.
Use IP+ when you don’t need extra sensitivity and are struggling to hear a weaker signal while a strong signal is transmitting 2 or 3 kHz away. This is similar to Yaesu’s IPO, Intercept Point Optimization, but not exactly.
IPO and IP+ both decrease the sensitivity of the receiver while improving the cross modulation characteristic of the receiver, helping it combat a strong signal on a nearby frequency that could wipe out a weak signal on the frequency you are listening to. But, the problem with IP+ is that it increases the noise floor during the process of improving the cross modulation characteristic. That is just how it works with the analog to digital converter that is needed for a SDR.
It is interesting to note that numerous IC-7300 owners report that IP+ yields little to no improvement in practical use. Rule of thumb? Leave IP+ off unless you think you need it. The amount of improvement it might yield would be more helpful during a contest, where selectivity is more important than sensitivity.
Yaesu’s IPO, Intercept Point Optimization, improves the cross modulation characteristic of the receiver but it also happens to decrease the noise floor at the same time. Rule of thumb? Keep IPO enabled always on 40m or below, where extra sensitivity is not needed and improved rejection of strong nearby signals is a plus. You also enjoy the added benefit of a lower noise floor. At 14MHz and higher IPO is optional. At 21MHz and higher, you will most likely need AMP1 or AMP2.
73, de N4HNH
I would love to see a series on a Flex Radio vs some of these others. Maybe someone will loan you their Flex...after all they can still operate it while you have it for a week or so 😁
Ha! Maybe someone will send me a Flex. I know a guy with a Flex, a FTdx9000, a FTdx5000, and a FTdx101D. He prefers the receiver in the 5000. I haven’t been to his shack. He is someone who hangs out on one of the 75m rag chew frequencies I sometimes listen to.
But Sherwood Engineering already answered the question. Flex 6700 is number 2 for RMDR, with a rating of 108dB. The FTdx10 came in at 107dB. The FTdx101D ranks number one, with 110dB. They’re all good radios with numbers like that. I just wouldn’t spend $7,000 for a Flex 6700, when I could get a FTdx101D for $3200.
But, if you read the footnotes for the Flex 6700 in Sherwood’s list you will see that the Flex 6700 that he tested at 108dB was a one-off. All other Flex radios tested by Sherwood come in at 99dB.
73, de N4HNH
Interesting upload Doug, thank you. It seems clear that you consider the DX10 to be the better rig. Given the lack of proper DSP on the 7300 (and I get the sense it doesn't really possess properly functional tools to deal with QRM/QRN), is the 7300 a viable rig for the casual operator? Or would they be better off elsewhere?
P.S. Are you on QRZ? Will try to contact you via QRZ to arrange a contact.
IC-7300 is a great radio for the casual rag chew operator. It’s also good for someone who is new to radio and needs a transceiver that is simple and intuitive. It’s just not a contest class radio.
I’m on QRZ.
73, Doug
on the 7300, why is the TX icon illuminated?
That’s just the way the IC-7300 looks normally, until you actually transmit. It’s rather confusing isn’t it? It doesn’t have a green RX light, like you might be accustomed to with Yaesu radios. Maybe ICOM ran out of space on the display for an RX indication, and they didn’t want to write the extra lines of code to toggle the TX light from red for TX to green for RX. What they did do, when you transmit, is fill the blank area around the letters TX with red and change the color of the letters TX, and the oval surrounding the letters, to white. Now that begs the question…If you can toggle from red to white, why not toggle from green for receive to red for transmit?
On the Yaesu, try going higher with DNR setting but switch the contour from negative to positive setting (like +8). Adjust contour frequency anywhere between 1800 to 2300 Hz. You get less noise and much better SSB signal clarity and readability.
I’ve done that. I get better results with DNR at algorithm 4, 5, 6, or 7 and Contour at 1900Hz, -18dB, and a width of 9.
As by my ears the 7300 has lower noise than the DX100.
Then you should use IC-7300 and not Yaesu. To my ears, the FTdx10 has the lower noise floor, and the DNR is superior to all radios on the market today from the big three.
73, de N4HNH
@@n4hnhradio In regards to the Noise reduction circuit I totally agreed, Yaesu NR is way better than any Icom, I have owned many Yaesu radios including the FTDX5000 and from Icom I owned the IC7851 and always found the Yaesu NR to be always higher performance.
Maybe you are alright about DX10 having less noise but the way you did that test video, it sound less noise in the 7300.
I definitively will like to try a DX10 but what have me stoped is the lack of averaging for the signal spikes which too darn fast.