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Author Topic: Calling and listening in 2 directions  (Read 435 times)

NO9E

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Calling and listening in 2 directions
« on: July 15, 2022, 03:54:07 AM »

PI4CC sometimes uses two phased beams pointing to different directions. While the amp transmits to both beams, on receive one beam is heard in the left ear and the other in the right ear. Is such practice common in top contesters? Can it be easily implemented using standard hardware?
Ignacy NO9E
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K3TN

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Re: Calling and listening in 2 directions
« Reply #1 on: July 15, 2022, 06:12:30 AM »

if you want to hear from both antennas simultaneously and separately, you first need a transceiver with two receivers built in and two antenna inputs - most modern high end transceivers have that or have an option for that.

Many ops put in switching for multiple beams to xmit on one or the other or both and with older transceivers with only one RX built-in, listening follows that but you don't get the L/R separation, you get both in both ears. To do what you want, you'd need more complex switching control to have the TX SO239 output of the xcvr going to the 2 antennas during a transmission, then when PTT drops have the second SO329 input (non xmit) on the xvcr  open/disconnected and have receive paths from each antenna to the two xcvr SO239 connectors.

There are many off the shelf computer controlled antenna switches that do all that.

If you have enough separation between the two antennas, or they are of different polarization, you can also (with a modern xcvr with 2 receivers built in) use them simultaneously for what is called diversity reception. Often when QSB hits on antenna, the other is more at a peak - short fades get filled in. It is really noticeable when done right.

Most multi-op and Single Op 2 Radio contesters have some version of that running. Back in the old days (80s/90s) I operated at the W3LPL multi-multi and we (and other big MMs) had beverage antennas on each band with two xcvrs and one op would call CQ while the other op could tune through the CQing and find multipliers or when things were slow find unworked stations calling CQ. Now most SO2R single ops are doing all that, too with multiple antennas. If you notice a slow response from a really loud station calling CQ, often it is because they are finishing off a QSO they were listening to on radio A while radio B was calling CQ!

73 John K3TN
« Last Edit: July 15, 2022, 06:26:26 AM by K3TN »
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John K3TN

W1VT

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Re: Calling and listening in 2 directions
« Reply #2 on: July 15, 2022, 07:12:04 AM »

Yes, when I was running my little pop gun HF station in contests I built a relay switching box to handle the left ear, right ear, both to both ears issue.
I found it very effective in the CW Sweepstakes, as I could copy stations on two separate bands and the same time. Sometimes the margin of victory was just a few QSOs.

Zak W1VT
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N4OGW

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Re: Calling and listening in 2 directions
« Reply #3 on: July 15, 2022, 07:49:20 AM »

PI4CC sometimes uses two phased beams pointing to different directions. While the amp transmits to both beams, on receive one beam is heard in the left ear and the other in the right ear. Is such practice common in top contesters? Can it be easily implemented using standard hardware?
Ignacy NO9E

I often split my 20/15/10 stacks in two different directions. For all three bands I have one antenna fixed NE and the other rotates.

I don't see much advantage to splitting them between radios/ears on one band, and the switching to do that would be complex. I can hear fairly well with the stacks split- if I need to hear a particular station better I just switch to that antenna. If the band really is open in two directions often it works well to switch to one antenna for receive but go back to both during transmit.

Tor N4OGW
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KX2T

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Re: Calling and listening in 2 directions
« Reply #4 on: July 15, 2022, 08:28:45 AM »

Back in the mid to late 1990's and very early 2000 I ran a small by comparison two crank op tower contest station with all monobanders but the lower antennas were always fixed on EU but the top ones had full rotation. Yes we could run stacks into EU but once we had seemed to work allot of EU we would slip the stack and place the top antennas to JA or SA depending on propagation which would be like spraying two area of the globe with RF like cats do around the neighborhood. This worked out extremely well not only to pick up mults but we were able to run JA and EU at almost the same time which added more contact in our logs then just pointing and shooting in one direction then having to abuse the rotors. It would have worked even better if we had another lower tower for like a tribander fixed into SA but on a 1/3 acre plot that was pushing the limits of that property.
We had a 3 element 40 meter F12 beam at 72' which worked well but I always wanted to change that antenna to two element phased on that 30' boom which would allow us to work EU and then work VK's and ZL's with a quick switch relay instead of rotating it all the way around. I never got a change to change that antenna but I would bet that would have save lots of time and rotor wear and tear with almost the same gain as the three element had but be more versatile plus lower wind load. If you look up the scores from that time span in the mid 90ies we used KF2ET, Then a special event  call of W2A running Multi Single most of the time but we did do a half ass multi multi in 1998 with three stations running full time. We tried to run 4 but the main house 100 amp breaker called it quits at 7am Saturday morning. Good thing Home Depot was a half mile away so we pulled the meter pan, pulled the main breaker and ran down to the store to purchase another one then re installed it and placed the pan back. In a little over a half hour we were back but only three station running! Good think one of the op's was an electrician so he could contact the local power company and have them place a new inspection tag on the meter.
Today you see many stations that always install just a simple tri band beam fixed to SA then be able to split the stack, having all your eggs in one basket is good if you just wanna call in a pileup for a new one but in contesting or group DXing diversity is the name of the game!
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K3TN

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Re: Calling and listening in 2 directions
« Reply #5 on: July 16, 2022, 04:48:24 AM »

I shouldn't admit this, but I believe since it is now 40 years later I am covered by the statute of limitations:

Frequency fights in contests are common and multi-multis tend to all try to occupy the low end of the band. The east coast has a big advantage in DX contests, the multis in the "flyover states" have to beam over the east coast stations to reach the big QSO/mult concentration of EU countries.

A certain 5-lander was very aggressive about either flat out stealing competitor's frequencies or trying to snuggle in 100-200 hz away on 40 meter CW where I usually operated at the W3LPL multi-multi operation. 40, along with 20m, was always a big money band in DX contests - you did not easily give up a good run freq if you wanted to win.

40M had a stack with 3 or 4 elements at 200' and 3 or 4 elements at 100' - the response was to turn the "low" yagi towards the SW and leave the high beam on EU and only listen on the top antenna vs. listen to both. Usually the five lander had to give up but would also pick up a few XE and central American QRP operators who were surprised to have us actually hear them!

I don't operate full time in contests anymore, so maybe I just don't hear them, but with the vastly improved filtering in modern transceivers, frequency fights seem much less common.

The new issue is SO2R stations that don't quickly reply to QRL? because they are working someone on the other band but are trying to maintain occupation of two frequencies at once.

73 John K3TN



« Last Edit: July 16, 2022, 05:08:00 AM by K3TN »
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John K3TN

NO9E

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Re: Calling and listening in 2 directions
« Reply #6 on: July 17, 2022, 04:52:44 PM »

The idea if Tor of switching on receive is simple. Perhaps in the US there are not as many different direction as in the EU.

The competition for frequencies can be intense, especially in SSB, with 40m being special. WAE makes it even harder by excluding some band segments. In that case hearing is paramount.
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WB2VVV

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Re: Calling and listening in 2 directions
« Reply #7 on: July 25, 2022, 07:38:42 PM »

I currently have a button I push on the controller of my SteppIR beam that adjusts the length of the parasitic elements and makes the beam bi-directional with no front-to-back on 20m thru 10m. This works out very well being in RI as I can aim at EU or stateside and still grab QSO points off the "back" of the beam, without struggling to hear weaker stations thru 20 dB of front-to-back isolation. There is not much loss of gain that I have noticed being bi-directional versus unidirectional.

Back 25 years ago when my QTH was in NJ and I was actively operating VHF contests, I found myself constantly turning my stacked 6m beams back and forth between SW and NE headings to work two pileups. Finally I took the 6m beams down and readjusted the elements after modeling them with YO (Yagi Optimizer) to reduce the front-to-back of the beams to only 10 dB, instead of 20 dB. This gave a 10 dB boost to the stations off the back so I could copy the weaker ones a lot easier and not have to take the time to keep turning the beams back and forth.

The benefit of beaming NE and SW at the same time has definitely helped me over the years.

This past June VHF contest there were very nice 6m band openings. With my current small unidirectional multi-band stack (a single beam on each of the bottom 7 bands on one mast) I almost missed out on making 6m EU contacts - had I not thought to to take the time to turn the antennas around 180 degrees "just to check". Being in RI there is only usually ocean back there but the conditions were good enough that I worked a number of EU stations on CW that were around 6 dB above the noise when I was aimed at them. With the front-to-back working against me while working some 100 grids stateside I would have never heard those EU stations had I not turned the stack around "backwards".
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K3TN

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Re: Calling and listening in 2 directions
« Reply #8 on: July 26, 2022, 03:31:33 AM »

SteppIR antennas' ability to also do a button push switch to reversing direction 180 degrees to switch to longpath is very cool, also. 40M in the afternoon, 20M in the morning (East Coast) are often times when both paths are wide open on both paths.

72 John K3TN
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John K3TN

K3XR

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Re: Calling and listening in 2 directions
« Reply #9 on: July 26, 2022, 04:21:33 AM »

Can also use bidirectional on the SteppIr.
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NO9E

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Re: Calling and listening in 2 directions
« Reply #10 on: July 26, 2022, 01:20:23 PM »

Bidirectional in StepIR means NE and SW, or EU and VK/ZL. But no NE and NW. Another option would be simply a high dipole.

Every serious contester has a beam fixed to SE. Perhaps more serious would also have beams fixed to W and NW.  Not too expensive with a beam like C3. Most serious stations would mostly have beams fixed to most popular destinations. With inexpensive home-made beams, this may be an economical route since expenses associated with rotators can be eliminated.
Ignacy
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KC0W

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Re: Calling and listening in 2 directions
« Reply #11 on: July 26, 2022, 03:44:48 PM »

 I vaguely recall reading about phasing issues while beaming separate directions using HF. Something about the signals cancelling each other out. Does anyone have any information about this or is it "fake news"?   

                                                                                          Tom KH0/KC0W 
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WB2VVV

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Re: Calling and listening in 2 directions
« Reply #12 on: July 26, 2022, 05:15:34 PM »

Yes, I have a Rotary 40m Dipole installed on the mast above my SteppIR beam, aligned with the boom of the SteppIR beam to avoid interaction. I orient my 40m Rotary Dipole so it favors EU to the NE and also US to the SW, and it works very well bi-directional without have to turn the rotator. At this point I am very used to knowing that 40m is always aimed 90 degrees off the upper HF bands...
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