Marconi's Sirio New Top One compared to my Sirio Gain Master

[Marconi]

I have probably posted this video before, but I just checked it out again and thought a look would be interesting. In this video I had the gain set on my Kenwood TS 570D at normal, without the pre-amp, and the signals were showing in the low end of the meter where the signals appear to be less effected by the RF Gain.

In this install I have a Sirio New Top One mounted at the same height to the mount for both antennas which were 36' feet apart. I was on SSB, but maybe you can get a sense of the difference between the signals these two made. The GM has a brand new run of LMR 400 about 100' feet long, and the NTO was installed with some >8 year old RG213/U about 60' feet, but had not been used very much.

I believe this video clearly shows the NTO, with the tip approximately 16' lower that the Gain Master as installed, indicating the best signal of these two at this time. I have two 40' foot push-up poles for this setup and both were extended out to the max...which made the mounts each about 36' feet high.

 

[vkrules]

Interesting comparison.At first glance the top one looks a whole lot better. What is the topography like were you are ?.
Also wondering did you ever try swapping the mounting positions to confirm results and void any differences in location and cable runs.. And also have you tried both antenna systems on short and long haul DX .

 

[Marconi]

Interesting comparison.At first glance the top one looks a whole lot better. What is the topography like were you are ?.
Also wondering did you ever try swapping the mounting positions to confirm results and void any differences in location and cable runs.. And also have you tried both antenna systems on short and long haul DX .

Yes I know VK, some of the pitfalls in testing like this. Yes I attempted to test many of my antennas on each mount alone with no other antenna around, but I probably didn't get video of all those tests. For the most part I found very little difference, but I also have the natural bias like others...and I didn't devote much time testing a single antenna.

I'm northwest of Houston about 9' miles from downtown. It is flat here along the Gulf Coast of Texas about 50 miles inland. I live along a 10' high ridge that follows a well known main north/south bayou in this area, and thus am a bit higher than most of the surrounding area.

I did make an effort not to do test if there was a chance the DX was rolling, and sometimes conditions were stretching in and out making signal vary before my eyes, and that too was a waste of time. For the most part, there were some exceptions however, I compared only receive signals...and that adds a big question to results. When I got the idea to do some signal testing and videos...I discovered the local gang of 8 to 10 folks I could depend on to be on the air most...did not like my asking for signal reports. The were mostly ham operators that hung around the local area on CB 39 for their own reasons, but probably felt they were better than doing radio checks on the air.

If I would have had it my way I would have only worked FM, but that too was not going to happen with my regular contact group, so I did what I thought might be the best and only thing...a compromise.

Below are some images of a few of my Signal Reports comparing the Sirio's New Top One vs. the Sirio Gain Master. VK, if they need some comments let me know. I probably have videos of each of these reports, but I believe the one for the video above is #26.

 

[vkrules]

Thxs Marconi,great reports as always. The reports show a much clearer picture and as you said really only a slight difference .

My questions are only driven by my curiosity and my wish to understand what and how you where testing.

I know how hard it can be to get direct comparisons and sometimes results are skewed just by the presence of the second antenna. The antenna that provides the best result locally sometimes proves not as good on Dx. And this can vary between short DX (100 to 1000 mile) or long DX(10000mile) due to takeoff angle or whatever.
Back when I was testing the GM against the Imax , that is what I found.The GM was 1 to 1 1/2 s points better on the long distance DX than the Imax ,but almost identical locally I could never really understand WHY ! The modeling software certainly didn't show it.

Sounds like your location on the ridge top is a good test location.
Would have been concerned if you lived down in a gully as this also tends to skew results and make height differences more critical. ( not always the way you think sometimes the lower antenna provides a higher pattern and gets out better)







.

 

[Marconi]

I know how hard it can be to get direct comparisons and sometimes results are skewed just by the presence of the second antenna.

Most of my radio life I've tended to consider all the CB verticals I have showing about the same signals...as long as the maximum current lobes were somewhat similar in height. Spacing between was 36' apart, and is all I have reasonable space for. My house faces NW and these two mounting stations are N/S of each other looking right down the center of the ridge noted earlier. I live Northwest of downtown, and most of my SSB traffic was N,E,W away from the Gulf. I talked very little AM.

I did see skewing of conditions, but I just made mental notes and tried to never do signal reports when I suspected DX was lurking about.

The antenna that provides the best result locally sometimes proves not as good on Dx. And this can vary between short DX (100 to 1000 mile) or long DX(10000mile) due to takeoff angle or whatever.

I believe DX adds a whole other set of variables for comparison work.

Back when I was testing the GM against the Imax , that is what I found.The GM was 1 to 1 1/2 s points better on the long distance DX than the Imax ,but almost identical locally I could never really understand WHY ! The modeling software certainly didn't show it.

I never like my Imax. I always thought it was noisy and performed on the weak side. I never noted as much difference as you.

Sounds like your location on the ridge top is a good test location.

I feel that most around me were in a pretty good locations for radio. I was not alone among what I considered good operating stations all over the flat lands of Southeast Central Texas. I was a regular member of a group of about 20-30 folks that fussed and discussed stuff on 36-39LSB...off and on for >30 years.

For the most part I mostly worked my radio when Skip conditions were out. I think that changed a little in the early 90's. The last Skip cycle was spotty for me, and now there is little to no local traffic at all. Many of my group has died, moved, or stopped radio...and seemingly none to take their place.

 

[M0GVZ]

Just watched your Youtube video and you have one of those voices I could listen to all day.

Did you plot the contacts out on a map to see if there was any skewing of the data due to the placement of the antennas? Just trying to see if there is a reason for the difference. One thing we've concentrated on in the various discussions on this forum is low angle take off but in our discussions I don't recall taking much notice of secondary lobes at higher take off that there are and on some antennas compared to others because they've got different elevation patters the difference in gain at higher take off angles of the various antennas could account for this to some extent at certain distances and/or station heights compared to the person doing the testing.

Its a shame the AGC isn't adjustable on the TS570 so you could run it real slow which would give a more constant signal strength on SSB.

 

[The DB]

One thing we've concentrated on in the various discussions on this forum is low angle take off but in our discussions I don't recall taking much notice of secondary lobes at higher take off that there are and on some antennas compared to others because they've got different elevation patters the difference in gain at higher take off angles of the various antennas could account for this to some extent at certain distances and/or station heights compared to the person doing the testing.

I've mentioned something similar to this multiple times in the past when referring to radiation angles, but no one ever seems to notice or get the concept. The thought was, if you have multiple antennas that, for whatever reason (height difference is the most likely) have different radiation angles, the antenna with a lower angle lobe might have its skip end up in farmland where there are few to respond as opposed to a lower antenna with a higher angle lobe whose skip comes down on, say, populated cities where there are many people trying to work skip. Which antenna will get you better results with? Even if the antenna with the higher "take off angle" is a far worse antenna, it will seem to outperform the antenna with the lower angle of radiation.

I think it was Captain Kilowatt has mentioned multiple times in the past that it isn't the angle of radiation that matters so much, but where the nulls are, although I think he was referring to beams for the most part when he said that, the concept still applies.


The DB

 

[Marconi]

Both of your ideas make sense. I've read folks discussing such things. I only compared the differences in RX signals. I used SSB because that is where the traffic I worked was. I only made an effort to note how far away the operators lived and what antenna they used. The terrain around me is basically flat, and I would suspect antennas in this area would only be effected by other ground conditions in this case and not the terrain.

When I was made aware of TX signals differences by a comment from the other-end, I took note. I didn't really analyze what might be going on however and I tried to avoid Skip conditions in my test.

Since I was able to model, I began to realized different shaped antennas made distinctive differences in the shape and size of the useful maximum radiated patterns. This is about the extent of considerations I've made regarding the issue you raise.

Regarding the AstroPlane/Starduster and a couple of other models to compared in the PDF file below, in particular here with models at 32' feet, where these two produce a rather wide and still useful maximum RF lobe. Within reason the gain values are close in this group, but these two look to have more useful lobes...that cover the lowest angle upward to near 40* degrees, while the other higher gain models produce a pattern that is a bit less wide 30* degrees and less wide.

IMO, this may have some bearing on things, but in the real world I don't ever recall comparing my CB vertical antennas where one was able to hear traffic while the other did not. Of course I have experienced the lack of or full copy issues before, and for sure when I had a beam working, but other things in the environment could have caused those results too.

What Captain Killowatt says also make common sense, but I am not into such aspect for the hobby.

Connor I do enjoy the videos you produce, it brings a ring of truth to your words for us all to consider. Thanks