Your Antenna Choice for Multi Receive.....

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I am curious what antenna system you are using to take advantage of the Flex SmartSDR's Multiple SCU and Slices. I have a 6600 on order and currently am running a 3 element Steppir beam that is only resident on one band at a time... in order to listen to multiple bands at one time how do you accomplish this task without sacrificing the level of receive that my current antenna provides? I would like to be able to use the SmartSDR and Flex 6600 to its fullest. Your inputs is much appreciated!
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Jeff-W7NEE

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Posted 8 months ago

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James Whiteway

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I plan to use either a trap vertical or a End Fed Half Wave antenna on the second SCU (receiver). My thoughts are for using Diversity reception and being able to null out interference with the second antenna. My main antenna at the moment is a doublet fed with 450ohm ladderline and a Johnson KW Matchbox. Works real well 80 - 10 meters. (not so hot on some of the new bands)
I see the second SCU as a way to experiment with antennas a bit more than I currently do. I'm too old to climb a tower so, a big beam is out of the question for that reason and being on a postage stamp sized lot!
james
WD5GWY
 
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KY6LA - Howard, Elmer

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I use my SteppIR MonstIR set to the TX band.  

You lose about 1S unit on other bands but the radio is so sensitive that I hear so much anyways that it really does not matter.   I have a Pixel Loop for the low bands that also hears pretty well... in fact, I tend to use it a lot for lower bands as it hears about 20% different calls than my MonstIR. 

I have tried various verticals over the years and found that they tend to work EQUALLY POORLY IN ALL DIRECTIONS AND ON ALL BANDS.  I find my SteppIR MonstIR still hears better on other bands due to some directivity than the vertical.  The one caveat is that on some very distance DX the low angle on the Vertical can beat the beam - but rarely enough that I took it down and sold it.

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Chuck - KJ6HT

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I second the Pixel Loop. It offers the additional ability to null out local noise with an inexpensive rotator.
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WX7Y

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The only antenna I can think of that will really give you the gain and preformance (maybe more) then your Antenna now has but work on multi-bands would be a log periodic beam type antenna and the same with your existing beam would require a rotator to point it in the direction you want to use, the Log has a MUCH higher front to back ratio then your 3 element beam has because of a lot more elements depending on the bands it is built to cover. 

Issue's with the Log periodic antenna is the physical size, wind loading and that much like a FAN dipole or other mult-band antenna they may have a little more noise then a single band resonant beam Antenna but with the higher front to back ratio this would probably not be the case.

Just my opinion which isn't worth much but there you go.
73's
Bret
WX7Y
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Varistor

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RX antennas have vastly different objectives compared to TX antennas. RX antennas don’t have to be large and/or require rotators.
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KY6LA - Howard, Elmer

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That is true only if you do not expect to hear as much on your RX Antenna as your beam.

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Varistor

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Yes, you are 100% right. I expect to hear much better than my stacks of beams. RX antennas are designed to be a lot quieter, exhibit better directivity (RDF), and have instant direction switching capabilities. I also expect them to offer polarization diversity. This is why I use both beverage on the ground and small vertical array RX antennas. Add this arsenal to the stacks and you can select the best antenna or combination of antennas for the specific band conditions.
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Ken - NM9P, Elmer

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Yes, and no.... it depends on the band, distance, and local conditions as to whether a receive antenna will receive better than your Transmit antenna. On low-bands, yes. On higher HF, probably not, due to gain, directivity, and takeoff angle advantages of the beam on a tower.

But I sure do wish I had room for a couple of beverage on the ground RX antennas for 160 & 80!
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Varistor

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There is a good reason why W2FU, K3LR, K1LZ, etc. use dedicated RX antennas on all bands, not just on the lower bands. The benefits of laser sharp directivity, polarization diversity, and instant direction switching are significant. Hi-Z and LZ1AQ type of active verticals and loops (loops don’t have to be vertical, they can be horizontal) are your best friend. You don’t know what you are missing until you use one.
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Varistor

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If you want to learn, go to


https://www.contestuniversity.com/files/


and read the sessions on RX antennas. Buy the ON4UN Low Band DXing book to understand the deep fundamentals on antennas.


If you just want an answer, the one I’d recommend is the 3 element 6 directions Hi-Z verticals sold by DX Engineering. IMHO it’s the best bang for the buck.
(Edited)
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K3SF

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hi

I use a Tennadyne T8, 8 element LPA at 45 Ft...
It cover 20 thru10 warc bands included.
http://www.tennadyne.com/specs&prices.htm

No tuning , max gain on any band all at the same time.

I have 6600m on order and can easily see it on the T8 copying signals on 20, 17, 15 and 12m.


As for a second antenna, i used either a 145ft OCF at 70ft which easily cover 80 thru 10
or 43ft Vertical which nicely cover 40 thru 10..I have used these two on 80m for good diversity reception.  The radio at that item was TenTec Orion II with two independent receivers

cant wait to try these antenna with 6600M

Paul K3SF
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Bill Billingsley

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How far from your TX antenna?
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K3SF

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The distant from OCF to the T8 is about 75ft.

The distance from the OCF to 43fter is also about 75ft
and that is off the far end of the OCF, so it is not broad side to the OCF

I no Longer have the Ten Tec Orion. I replaced it with flex6300 which i traded in for the 6600M

My property is about 2 acres which is mostly wooded with some very tall trees. The tree height averages around 130ft. Some taller and some shorter.  Last tree i had harvested was 140ft Black Walnut and when checking the growth rings it put the tree in the 400 year old category.

Paul K3SF
(Edited)
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Bill Billingsley

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Thanks. I plan to set up a RX vert at 150 ft from the tower.  The antennas are up 85 ft.  I am on open prairie with no trees.  I can't go too far out or I'll have to protect it from the cows (ant and coax).

Bill, N5IR
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Steve Jones

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Whilst I have now sold my 6300, in favour of dual scu Anan 7000dle, until such time as the 6600 and 2.xx offer me what I want/need in my station for lf/hf/vhf, I can still comment on this antenna query:

I am using a wire elements heavy duty spiderbeam on hf (3 wire ele on 20m and 15m, and 4 ele on 10m all on 10m fibreglass boom and sat on top of a push up 10m spiderbeam alu hd mast.  I have a 1/4 wire vertical hanging in a tree with two elevated wire radials for 40m which works well on dx. An 80m inverted V up in my biggest tree at 20m agl; and a low 160m inverted v dipole in another tree some distance away in an adjacent field.

I have all of these antennas coming into the house and into my 4o3a antenna genius 2x8 port remote switch, which sits in the walk in cupboard behind my bedroom shack, where the anan 7000dle also lives, with both connected to my cat 5 lan connection.  I switch different antenna to either port A or port B on the antenna switch using the desktop app from 4o3a rather than auto selecting, as I prefer to manually switch different antennas instantly to try different antennas on dx signals.

I tx on the spiderbeam  using port A on the antenna genius switch, as its resonant on all three hf contest bands. I can have the same scu and antenna in use on a second panafall to monitor one of the two other hf contest bands. I connect port B from the 4o3a antenna switch to the Anan's second rx scu port, and either use diversity rx on one of the wire antennas, or I can monitor 40m or 80m or 160m on the second scu rx port with a second panadapter during a multi band contest. I also have my 7 ele 6m beam connected to the antenna genius, so I have the option of having the second rx and panafall looking at the 6m band (or 4m via transverter port when I put a tvtr back in the shack) whilst I am working hf on the spiderbeam or the dipoles/vertical.

Worked a weak VK a few weeks ago on 80m ssb using the 80m dipole @20m agl for tx, and on rx I used diversity and phasing option to null out some noise using the 40m wire vertical on scu 2 / rx2 - which enabled me to hear the VK much better and work him with just 100w :-)  First time I have used diversity function on any radio and I am now in the process of installing a k9ay rx array on an ex army fibreglass mast so that can be used for diversity and be switched in different directions too.

I am finding that the noise reduction 2 position in openhpsdr mrx ps in combination with the (wnb equivalent?) SNB control is much more effective than the NR was on my flex 6300. I am hoping that flex will further develop the smartsdr 2.XX to match or exceed the performance of the openhpsdr mrx ps software later this year, and the same for the ANF which also works better than in smartsdr 1.11 .  

I used to use a tennandyne T8 log periodic at my previous home on Anglesey isle eu124, as the second (mult) antenna and it was a really effective dxing and mult yagi on a second tower.

Next project this summer is to put up a four square for 40m to get some gain and directivity on 40m.

Early days here with the anan 7000, but I am liking diversity already, and the pure signal pre distortion certainly works well in cleaning up what was already a clean tx signal with my 6300. I have a lin amp uk gemini 1kw solid state amp on order, as that has pre distortion sampler on board to feed back into the anan. I am taking a bit of a break from major contesting this year, so more experimenting with antennas and diversity will suit my reduced time for radio.

I am looking forward to hearing all of the 6600 and power genius amp reports on here in the next few weeks, as I still plan to buy a 6600 and the bigger amp once both have been developed a bit further and have been out in the field and in contesting use for a while. I don't anticipate having any problem selling on the anan 7000dle as more and more people are seeing the benefit for dual scu for dxing, diversity and contesting.   

73

Steve gw0gei /gw9j
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Brad

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I think my Hex may do a good job on 10- 20. No need to retune or switch antennas.  A loop on 40 thru 160 for receive only  and a 133 ft. wire for transmit and receive with a antenna switch to select Hex or Wire. The second port will be the 6 meter antenna. I just hope 6600M will tune a mismatch of 5.5 so can get rid of tuner.
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WH6HI - Pat

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What antennas work well has been universily asked question for as long as radio technology has exited. I love the subject. In my own most recent experience, I used a vertical for the last five years. But I always wanted to get back to the next level of antennas that not only transmitted well, but could hear very well and deal with local noise.
My vertical of choice was a Zero25 GP4010. Along with this antenna I used a folded dipole. They were used in my previous home location in MA. Was never satisfied with the noise with the vertical, even with the filtering effect of a tuner. Always found that I needed to use the TFD to hear weak stations. On the other side of the coin the vertical, with its low angle of radio wave was gang busters for DX. Earned DXCC as well as WAS. And many of the eQSL awards.
Then I moved after retirement to Hawaii. I set up my vertical and wow, the noise really bad. 40 meters on SSB was very difficult on the local 40 meter inter island net. Could not hear About 50% of the stations on the net. I needed a solution, turned out to be an expensive solution. After much research, my decision was Shielded Magnetic Loop. Made a huge difference in my reception. On 40 meters my noise dropped 10 to 15 dB, and gave me 100% copy on all stations in the net as well as great performance on digital modes. As usual for the vertical I had very good transmit performance.
After about 2 years of living here in Hawaii, I began to feel I needed more and began researching a much bigger project. Switching to a full set up, that is tower, beams rotors, the whole ball of wax. I sit here now, project completed. Here is what I have now. 40 foot tower with 20 to 10 meter log periodic, with a 40 meter rotory dipole above the log. For 80 meters, I have a double bazuka. I chose these antennas because the research I did pointed in the direction of being quiet antennas that heard very well.
My noise issues mostly fall 14mhz and below. All three antennas are significantly quieter by about 5 to 8 dB. But also had a significant improvement in signal strength. A couple of things were apperent to me. In the case of the log, even though it is a broad band antenna, signals fall off significantly below 14 MHz. On the 40 m rotary dipole, it is a slightly shortened antenna ant signals fall off significantly above and below, acting as a band pass filter. The 40 m RD works as well as my mag loop in respect to noise, with a very good signal boost due to its mounting height of 50 feet.
So overal putting up a tower, with a reasonable gain in height with horizontally poletized antennas. Has been a big change in my ability to radiat and hear signals. If you all care to see my new antenna system, go to my QRZ page, WH6Hi

Aloha, Pat
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Varistor

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The reason your vertical was so noisy is because of common mode flows. As a general principle, TX verticals require 1) extensive radial system to minimize ground losses (at least 32 radials) and 2) solid common mode chokes.
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Ria - N2RJ, Elmer

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To take full advantage you need a multiband antenna. If you want to receive everything then get a log periodic.

You can also use a multiband Yagi such as a tribander. GXP, JK, momobeam etc.

When I’m skimming I use a vertical. The reason for this is that I want to hear signals that I have a good shot at working, not something down in the noise that I have to use the yagis to receive.
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WQ2H - Jim Poulette

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Great topic - I've had good luck using two 8-band Buckmasters (OCFD) mounted perpendicular to each other with several separate noise cancelling antennas. I've always manually switched between the two Bucks, but I'm very interested in trying the diversity reception.

73 Jim, WQ2H
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Ken - NM9P, Elmer

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I have. T-11 Log Periodic for 20-6 and love it. I use a variety of verticals, inverted L’s and dipoles for 30-160. I have been contemplating building a short vertical receive antenna for monitoring other stuff while transmitting on another slice and band.
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Johan SE3X

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Using a 2x6 antenna switch to share antennas betwen 2 radios (Flex 6500 and 6700) or to let the 2 SCU's in my 6700 do SO2R. As RX antenna I have a 80m loop @10 feet a bit away from the house and TX antennas. Loop mainly used for RX on 160, 80 and 40m. Adding either a directional small delta loop array or maybe a BOG before snow starts falling.

Having separate low noice antennas for RX makes a huge difference. I'm lucky to have the space, not all are.

(Edited)