[amsat-bb] Working in the "Field"

[Hasan N0AN]

Brad and all other new satellite operators:

I'm not sure what advantage or purpose an SDR 'computer screen' has for FM
Birds. They are single channel, so being able to see the entire passband
(of 12 kHz, for example), is of little or no value. I'm not sure why you
are taking what appears to be a snarky swipe at SDRs when they have no real
applicability to FM satellite operation. One can, of course see the QSB of
the satellite and perhaps time your calls to the peaks, but from what I've
seen, the experienced FM Sat ops do a very good job of recognizing the
peaks and valleys and taking advantage of them. (both uplink and downlink)

The primary issue with the FM birds is FM capture. People have learned that
the higher their EIRP , the better chance they have of capturing the
receiver and being heard. It is quite obvious to me that there are many
stations running very high EIRP. By the way, EIRP = Transmitter Power
Output + Antenna Gain - Feedline Loss . So saying one is running only 5
watts with a handheld yagi that has 10 dB gain on 70cm, means one is
running 50w EIRP (feedline is so short, loss is ignored), which ought to be
easily enough to put a good signal into the satellite. When it doesn't, the
meaning is obvious...lots of others are running EIRP of hundreds of watts.
================================================
Comments below are about Linear Birds, NOT single channel FM Birds

The linear birds, on the other hand, are MUCH more demanding of operator
proficiency, if for no other reason than to prevent unnecessary
interference to this precious resource we call a downlink passband.

I am not inclined to hand out any medals to rovers and grid chasers on
linear birds who destroy the ability to use the satellites for everyone
else,  primarily due to their incompetent or indifferent operating
practices. I'm not singling out Rovers/Chasers, the satellite passbands are
loaded with similar behavior  from those not doing Grids. I am taking issue
with what too often appears to be the self appointed entitlement of those
who Rove or Chase grids to trash a linear bird's passband simply because
they are "handing out rare grids"

These include, but are not limited to:

1. Failure to have doppler control and as a result sliding up the band
QRM'ing existing QSOs calling "Gridline xx xx" , as if their "in the field
ops" entitle them to make a complete mess of the passband.

Not all rovers/grid chasers are this way, *some are quite good at doing
manual doppler*. They are to be recognized and appreciated for their
efforts and accomplishments, not to mention their considerate operating
practices. Unfortunately, from what I have observed from daily operation on
the linear birds, they are far from the majority.

2. Inability to hear themselves which falls into two categories:

a. Poor receiving setups. Being "in the field" does not justify poor
receiving setups. (not really a problem for most FM birds, as they are
ridiculously loud on Mode B, at least) A handheld yagi and a SSB receiver
are quite adequate for most Mode B birds, but if not,  it is not cumbersome
to add a preamp to the receive side.

b. A complete lack of understanding of the relationships between the uplink
and downlink frequencies. They are VERY predictable. The fact that so few
of the abusers have taken the time to learn how this works is downright
embarrassing. One need not hunt if one bothers to learn these
relationships. There is even computer software that will calculate it for
you.

This results in people calling CQ while sliding up the band all over the
existing qsos with gigantic signals...yet they can't seem to find
themselves. We call them, they don't answer, they keep calling CQ. I cannot
count the number of times I have answered a very strong CQ with my signal
25 dB out of the noise (with the CW beacon being 30 dB above the noise),
only to have the op continue to drone on calling CQ, because they either
are NOT listening on their downlink frequency, or their receive setups are
so compromised that they can't hear....and they continue to slide up the
band, trashing every qso in the process.

We also have the "mad ditters" trying to find themselves as they change
their transmit frequency hoping to find themselves on "some" receiving
frequency. They go up and down the band, drawing a very pretty serpentine
display on an SDR.

3. Running excessive power, both the Rovers and those calling the rovers so
they can get that "I just gotta have it" grid.

Another issue that comes into play with linear birds (that is not as much
of a factor for FM Birds) is that the downlink power from the satellite is
a shared resource, i.e. *the downlink power is divided among all the uplink
signals and is assigned in proportion to the uplink strength.*

*It is for this reason that good operating practices dictate that one's
downlink signal strength should NEVER exceed the strength of the CW beacon.
If each station practices this, then the power is shared equally for all
users. *

This is where an SDR or most recently, the IC-9700s come into their glory.
Properly set up, they can "see" the entire passband  and the beacon at the
same time. *So when they transmit, they can not only hear their own signal,
they can see how it compares to the strength of the beacon in real time.  *(and
adjust their uplink signal strength accordingly)

Belittling SDRs and well equipped stations while operating in the blind
(not knowing your signal strength with respect to the cw beacon), and
simultaneously trashing the passband all the while assuming one is entitled
to do this because one is 'in the field' is NOT the way to go. In-the-field
can be done very, very well. Well equipped stations can be operated very,
very poorly. This should not be about SDRs, good equipment, rotors, yagis,
or whether one is 'in the field' or not....it is about three primary things:

Good doppler control (manual or computer)
Reasonable receiver/antenna sensitivity/performance
Properly managed uplink power (EIRP)

...discounting actually knowing how to use one's equipment and features

The other thing I hear is "Well, I was only running 10 watts". That means
nothing, absolutely nothing. Depending on many variables 1 watt is plenty
and at other times 25 or even 50 watts is required to be beacon strength,
but no louder. *That is why for linear birds (ssb/cw), it is absolutely
essential to be able to follow the cw beacon strength in near real time.
SDRs and IC-9700s permit this.*

If one cannot do this, then it is likely that you are power robbing the
rest of the users on the bird. I see it every day on every linear bird. At
the very least, take the time to check for the beacon strength several
times during the pass. Learn how your signal impacts the bird at various
times during a pass.

It takes experience and it takes practice.

*Every pass, even of the same bird is different and every part of every
pass is different.  Proficiency requires practice.*

The power requirements to be at CW beacon strength vary all over place
depending on not only elevation of the bird, but also the nature of the
path geometry of that pass with respect to your qth. (Look angle).

Ignoring all these factors (doppler, rx sensitivity, uplink power
management, being on the frequency of the station one is calling, etc.)
makes for a miserable satellite experience for all involved...and the
response of far too many when they can't hear themselves is to crank up the
power.

In closing, there are quite a few experienced sat ops who are more than
willing to help any new op. We were all helped back in the days of Oscar 6,
7, 8, 10, 11, 13 and 40. Hours were spent reading, studying, asking a
bajillion questions and getting high quality, informative answers.
Eventually, some skills were developed that helped everyone, including
ourselves...and I should mention that back then, we did everything
manually, doppler, slide charts for satellite tracking, manual rotor
movement (try doing AZ/EL rotor tracking and manual doppler at the same
time....we did...it was like playing a piano with your left hand and
spinning a knob with your right, while listening to your out-of-phase
downlink signal and talking at the same time.

What is most frustrating is to have pass after pass go by with the same
people doing the same things listed above and have no way to contact them.
I have personally emailed dozens of ops with help, including video
recordings of just what their operating practices were doing to the
satellite passband. The responses have been uniformly positive.

The unfortunate situation is that some of the worst offenders don't have an
email listing. So: they can't hear you on the bird trying to help them.
They can't get email, so the only way is to send them a letter. I'm really
not into sending out form letters any more than I am getting them.

Hopefully, my comments will help those new to the linear birds.  I am happy
to work with anyone on any of the Mode B (70cm up/2m down) birds. I can
provide a video/audio recording (very high quality mp4) to anyone who wants
to know what their signal is like, how it compares to the beacon, how it is
impacting others on the satellite and how signals vary during a pass.

This entire series of comments is not about being perfect, or not making
mistakes, or being afraid of criticism. The key is to get better, to become
more proficient at satellite ops. Learn from mistakes. Seek out help.
Listen to experienced ops. Ask questions like crazy.

Not knowing any better is not a fault, but staying that way, in the face of
readily available information, most certainly is.

73, N0AN
Hasan


On Thu, Oct 1, 2020 at 12:12 PM Gerald Witalec via AMSAT-BB <
amsat-bb at amsat.org> wrote:

>  Good one Brad. I have my TH-D72A and Arrow antenna ready for action.
> Jerry...W8RQM
>
>     On Thursday, October 1, 2020, 10:50:55 AM EDT, Brad Smith via AMSAT-BB
> <amsat-bb at amsat.org> wrote:
>
>  <More arm chair operators should attempt to make QSO's in the field. They
> might get an idea of what manual everything entails.> What I see is ops
> sitting in front of their SDR computer screen, and criticizing someone who
> is out in a field, holding an Arrow in one hand and an HT in the other, and
> combating fading, because they missed something in a call, or did something
> that they don't like. I only work satellite portable and don't know the
> luxury of working from a temperature controlled room with computer screens,
> rotating and elevating antenna, pen and paper, etc. But we handheld ops are
> still giving them the grids.  Brad KC9UQR
> _______________________________________________
> Sent via AMSAT-BB at amsat.org. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
>
> _______________________________________________
> Sent via AMSAT-BB at amsat.org. AMSAT-NA makes this open forum available
> to all interested persons worldwide without requiring membership. Opinions
> expressed
> are solely those of the author, and do not reflect the official views of
> AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb
>