Updated RST Audio Panel?

[N523RV]

Jim,

I had emailed you late last year inquiring about upgrades to your audio
panel product. I think you indicated that you were working on a new
version? If that is the case, do you expect it to be available any
time soon?

I think there might be a market for a scaled down version of an audio
panel.. unlike the current model which has many functions not used in
today's homebuilt.

- 2 place intercom
- 2 com inputs
- Stereo
- 3-4 unswitched inputs for devices that generate alarms
- switched input for stereo.
- marker beacon receiver/lights
- updated 'design' to look a bit more modern.

Things that I personally don't see a need for: ADF, DME, Speaker, dual
NAV's.... but that is just my personal opinion as I'm sure some will
want some of these functions.

Thanks!

Matthew

[RST Engineering]

"N523RV" > wrote in message
oups.com...
> Jim,
>
> I had emailed you late last year inquiring about upgrades to your audio
> panel product. I think you indicated that you were working on a new
> version? If that is the case, do you expect it to be available any
> time soon?

Which is why we almost NEVER tell people what we are working on. I get
something on the order of two hundred emails a day, and at least three or
four about "when is your new flipperdegibbet coming out". They come out
like babies, when they are damned well good and ready. However, as half a
dozen of you in this newsgroup found out last year with the four place
RST-443 permanent mount intercom, if you keep reading this newsgroup you get
a beta unit to assemble for free.


>
> I think there might be a market for a scaled down version of an audio
> panel.. unlike the current model which has many functions not used in
> today's homebuilt.
>
> - 2 place intercom

4 place is as easy as 2.


> - 2 com inputs

Three com inputs. Too many ham radio or business band folks in here.


> - Stereo

NEVER!!!!!!!!!!!!!!!!!!!!!!! (See rant at the bottom of this post.)


> - 3-4 unswitched inputs for devices that generate alarms

Will never provide an audio input that can't be switched off. Suppose it is
an oil pressure failure alarm and it suddenly goes off a mile outside the
middle marker? What you going to do? Land immediately? You are about to
do that anyway, and having an alarm in your ear at that point in time is
about the last thing you want.


> - switched input for stereo.

Switched and prioritized input for monophonic "entertainment radio"


> - marker beacon receiver/lights

External optional marker receiver with lights on the panel.


> - updated 'design' to look a bit more modern.

So far, no complaints on the current mechanical design as not being
"modern".


>
> Things that I personally don't see a need for: ADF, DME, Speaker, dual
> NAV's.... but that is just my personal opinion as I'm sure some will
> want some of these functions.

Single switch marked "nav" with six or so inputs for all the nav radios --
ADF, DME, NAV1, NAV2 ... and they all come on at once. You don't want to
hear the DME? Turn the DME volume control down.

Other goodies ... digital 60 second recorder with an option to play it back
on the transmitter line (perfect clearance readbacks in the controller's own
voice) and a few more I'm not willing to share right now.


******************************

Stereo In The Aircraft

RST does not produce any stereo intercoms, audio panels, headsets, or other
devices that reproduce stereo music. If you are absolutely determined to
have stereo in your aircraft, you might just as well stop reading now,
because anything we have to say isn't going to change your mind.

We made a conscious business and engineering decision not to produce any
product for stereo. There are good aviation and engineering reasons for
this.

First, a little background music or listening to the ballgame in a cockpit
environment isn't all that bad. Sometimes flying is miles and miles of
nothing but miles and miles. On the other hand, I know from my own love of
music that when there is a particularly good cut playing on my home stereo
and I have the headphones on (try "Sweet Sir Galahad" by Baez or "Minstrel
Of The Dawn" by Lightfoot at somewhere slightly below the threshold of pain
in the 'phones to see what I mean) that I get totally lost within the music
and the world just sort of blurs away. Just about the LAST thing I want in
an airplane is a pilot that has zoned out on music and is just holding the
controls to have something to do with their hands. That's item #1.

Second, stereo is expensive. Yes, I understand that FLYING is expensive,
too, but to go to the expense of specially-designed headphones, intercoms,
audio panels, and all the rest of it seems to us to be on the other side of
reasonable. Our company thrust has, and always will be, to make flying
affordable for everybody. That's point #2.

Now to the engineering stuff. Suppose you try and take your stereo headset
and fly in somebody else's airplane that is "regular airplane". Will your
stereo headset work without the trick little switch on the cable to convert
it to a monophonic headset? No, you will hear one ear of the conversation
only. And what did that little switch do? It put both earphones in
parallel, which cut the impedance of the headset in half. Properly
designed, this MIGHT not be noticeable to the aircraft radio, or it might.
Since airplane radios weren't designed to figure out whether or not you were
messing around with a stereo headset, the manufacturer didn't worry about
making sure his radio would drive that low of an impedance.

Even worse, if somebody else takes his standard aircraft headset and puts it
into your stereo airplane jack, it will short out one of the channels.
Depending on the design of the intercom, the best you can hope for is that
one stereo channel will be dead in everybody's headphones. Second worst is
that the short on that channel will blow out the amplifier for that channel.
In a really lousy design, that short will cause the whole intercom/audio
panel to fail, leaving you without any headphone audio at all.

Given all these reasons, RST has decided not to produce any stereo
equipment. While it probably won't sway your decision for stereo in your
airplane, we thought you should at least consider these problems.

Jim

**************************************************

[Carl / KG6YKL]

Elmer,

No wonder you get 200 e-mails a day. That audio system sounds
awesome. Let me be a beta tester. oh, oh, oh, me, me, me.

Carl

> if you keep reading this newsgroup you get
> a beta unit to assemble for free.

[Carl / KG6YKL]

Jim,

I just looked around your website. I didn't see any kits for a
homebrew SWR meter. Do you have anything? Or a recommendation on
plans to make one. Personal interest is in both 123MHz and 146MHz
range. Also, I have never understood the effect of transmit power.
Different SWR companies talk about specific transmitter powers...

Carl

[RST Engineering]

"Carl / KG6YKL" > wrote in message
news:j4U8e.55964$lz2.47289@fed1read07...
> Jim,
>
> I just looked around your website. I didn't see any kits for a homebrew
> SWR meter. Do you have anything? Or a recommendation on plans to make
> one. Personal interest is in both 123MHz and 146MHz range.

When Rat Shack had one for $20 or so, there was no incentive. I might just
do one now that theirs is gone.


Also, I have never understood the effect of transmit power.
> Different SWR companies talk about specific transmitter powers...


I don't understand the question. Antenna VSWR doesn't change from
microwatts to megawatts (with the possible second order effect of the
megawatts heating the elements to the point that they expand in diameter and
length).


Jim

[Bushy Pete]

And me too please Jim!

I promise to take lots of pictures of me tryimg to solder it together to
NASA spec's in the middle of the outback. If only I can remember all those
steps I was taught as an apprentice all those years ago when I did "High
Reliability Hand Soldering", otherwise known as solvent sniffing sessions!
Of course, this means that I'll have to try to decifer all my old
hand-written class notes!

;<)

Pete


"Carl / KG6YKL" > wrote in message
news:3PT8e.55963$lz2.11481@fed1read07...
> Elmer,
>
> No wonder you get 200 e-mails a day. That audio system sounds
> awesome. Let me be a beta tester. oh, oh, oh, me, me, me.
>
> Carl
>
> > if you keep reading this newsgroup you get
> > a beta unit to assemble for free.

[Carl / KG6YKL]

> I don't understand the question. Antenna VSWR doesn't change from
> microwatts to megawatts (with the possible second order effect of the
> megawatts heating the elements to the point that they expand in diameter and
> length).

Well, if you don't understand the question it is only because I don't
understand enough to ask an intelligent question. When I look in the
HRO catalog may of the SWR meter ads have multiple power settings
(15/150/1.5KW). I assume that you simply select the appriate range
that is just greater than your rig. I was just wondering why the
range mattered. Why not just use the highest power range if the
sensitvity doesn't vary significantly with power.

Even if they cost the same, I'd rather build a nice kit than buy one.
I'd like to understand more about how they work and there is nothing
like getting your hands dirty to understand something.

Carl

[Rob Turk]

"Carl / KG6YKL" > wrote in message
news:qtY8e.56016$lz2.20887@fed1read07...
>
>> I don't understand the question. Antenna VSWR doesn't change from
>> microwatts to megawatts (with the possible second order effect of the
>> megawatts heating the elements to the point that they expand in diameter
>> and length).
>
> Well, if you don't understand the question it is only because I don't
> understand enough to ask an intelligent question. When I look in the HRO
> catalog may of the SWR meter ads have multiple power settings
> (15/150/1.5KW). I assume that you simply select the appriate range that
> is just greater than your rig. I was just wondering why the range
> mattered. Why not just use the highest power range if the sensitvity
> doesn't vary significantly with power.
>
> Even if they cost the same, I'd rather build a nice kit than buy one. I'd
> like to understand more about how they work and there is nothing like
> getting your hands dirty to understand something.
>
> Carl

VSWR is a ratio. It's the ratio between the power being sent to the antenna,
and the power being reflected back from the antenna to the transmitter due
to mis-match. Measuring VSWR is usually a two-step process. You first set
the instrument to measure transmitted power by adjusting a potmeter so that
the needle reads full scale. You then flip a switch to measure the relative
amount of power coming back. There's different versions that use two needles
or two instruments at the same time, but the principle remains the same.

The reason for having different power ranges is that first step of setting
the instrument to full scale. It would be near impossible to adjust with
1.5KW input if the instument was sensitive enough to also reach full scale
with just 5W. At least not with the parts used in a $20 Radio Shack model
;-) A slight error would smoke the instrument.. On the other hand, if the
instrument would be fixed to 1.5KW, the 5W handy would never get the
instrument to read full scale. So you have to manually pre-select the proper
range.

There's electronic versions out there that can auto-range but they are
usually not available to mere mortals.

If you want to build one, get the ARRL Ham Radio handbook, they usually have
one or two designs in it.

Rob

[Denny]

Ummm, the Lightspeed 20-3G I use in Fat Albert has the stereo / mono
switch... Flipping it back and forth does not change the audio level,so
they must be doing more electronically than just gobbing the
transducers in parallel for mono... Other than that, I usually only
listen to the ball game on the ADF anyway, so stereo is of no benefit
to me... OTOH, we are leaving Friday for ~30 flying hours through the
deep south, so I may be a babbling idiot by the time I get back from
listening to country music and revival preaching on the AM band... I
may have a different viewpoint about stereo by then...

cheers ... denny

[COLIN LAMB]

"I may be a babbling idiot by the time I get back from
listening to country music"

FAA controllers are instructed that if they hear country western music in
the background of a pilot calling, that they are to divert all other
aircraft which might intercept it. If the pilot asks for a repeat of
instructions, they declare an emergency for you.

I thought that was keen, and tried to keep the volume upwhen contacting ATC,
but found a controller in Texas that simply asked me to key the mike and not
say anything.

Colin N12HS

[Dave S]

Heh... I'd love for his audio panel to have the "crew-Pilot-all"
function on it... but I'm comin down to the wire and will prolly end up
just getting it as is, SOON..

Dave

N523RV wrote:
> Jim,
>
> I had emailed you late last year inquiring about upgrades to your audio
> panel product. I think you indicated that you were working on a new
> version? If that is the case, do you expect it to be available any
> time soon?
>
> I think there might be a market for a scaled down version of an audio
> panel.. unlike the current model which has many functions not used in
> today's homebuilt.
>
> - 2 place intercom
> - 2 com inputs
> - Stereo
> - 3-4 unswitched inputs for devices that generate alarms
> - switched input for stereo.
> - marker beacon receiver/lights
> - updated 'design' to look a bit more modern.
>
> Things that I personally don't see a need for: ADF, DME, Speaker, dual
> NAV's.... but that is just my personal opinion as I'm sure some will
> want some of these functions.
>
> Thanks!
>
> Matthew
>

[Netgeek]

Not that my 2-cents is worth any more than anyone else's 2-cents,
but - for the sake of discussion - a comment or two:

> "RST Engineering" wrote in message
> Other goodies ... digital 60 second recorder with an option to play it
back
> on the transmitter line (perfect clearance readbacks in the controller's
own
> voice) and a few more I'm not willing to share right now.

I like the "recorder" feature/idea alot. But - the thing that would make it
really cool would be an "instant playback" of the *last received message*
only. This may be of variable length. A processor could track this to some
extent (perhaps by monitoring the break on the squelch) but in reality just
listen to any approach frequency and note the amount of overlap between
the controllers and the respondents - deciding where to "mark" the
beginning and end of separate transmissions received would be tough -
but it could be probably be fine-tuned to give some fairly good results.

The playback of the controller's message on the transmit side seems to
be of limited utility - IMHO. Here's why - The purpose of the "readback"
on your part is to demonstrate that you have in fact received and understood
the instructions. Playing back the controller's own voice message on the
transmit doesn't demonstrate that you really DID hear and understand. It
might be fairly cool in the vent of a "dispute" - you could let them hear
their very own words - but, other than that, doesn't seem that useful.

A really useful feature in the intercom would be "Automagic Gain Control"
and levelling of the outputs. Some of the newer and more expensive
Comms units feature this (for a hefty price premium) but it sure seems to
make more sense to put this in the audio panel where all the different and
disparate levels actually come in! What difference does it make if my
new Acme Nav/Com has levelling if it doesn't match the levelling that may
be going on in my other widgets? Analog Devices has a nifty device with
their SSM-2166 which has a VCA and alot of options for compression.
There are others (e.g. Thatcorp.com) which can provide dual slope
compression/limiting/gating, etc.... Personally, I think this would make for
an attractive set of options.

I could be wrong (not that it's ever happened before 8-).... but those are
some of my comments anyway. I'm sure the final product will be great
with or without any of these features.

Bill