Display = Field Strength & % AM

Bluebird@Apex

Bluebird@Apex

Filing Flight Plan
Joined
Feb 28, 2017
Messages
8
Display Name
Display name:
Robert L. Stasny
I have searched & E-mailed Jim Weir (has a column in Kitplanes magazine = Aero'litics) about a display that I would like to build & place @ our run-up pad on our airpark.
The reason is;
  • Aircraft VHF (108 to 139mc)is Amplitude Modulation & simplex
  • Transmitters/pilots/crew have NO idea what they are sounding like to others on frequency i.e. weak modulation or over modulation.
  • Also, do not know a transmitter's relative field strength.
  • All could be supplied visually via LED bar lights @ a run-up pad.
I saw an old low frequency FS & %AM using a CK722 transistor, Ge diodes & sensitive needle meters (?50ua).
I lost track of where I saw it. But would require extensive design change for what I would like to build & be stable through outside temperatures.
Can you help??
Thank you...
John @ Apex airpark. Retired GTE electronic repair station & living a grass-roots flying dream.
I hold an A&P-FAA, PVT/SEL Pilot, 1st class Radiotelephone + radar FCC, & getting old.....
I have many discreet electronic parts (vacuum tubes to Hex Pwr MOSFET) collected over my 60 years of tinkering.
 
Bluebird@Apex said:
Transmitters/pilots/crew have NO idea what they are sounding like to others on frequency i.e. weak modulation or over modulation.
Click to expand...

Why not just pick up a superawos that has automated "radio check" functionality built in?
 
Not familiar with a "superawos" .
How does that, at a run-up pad, let a pilot know just how his transmitter is getting out & it he/she is over/under modulated??
With pilot renters, using their head sets in a rented A/C, that are different from the head set that the % modulation was adjusted to?
I monitor our CTAF=122.8mc & there are both pilots that sound like they swallowed the mic or it is in the back seat when they transmit.
A properly modulated AM transmission will be the clearest & have the longest range, where the receiving operator doesn't have to turn up the volume for the under modulated, then get their ears blown away with a proper or over modulated transmission.
I have a Chushman tester, but I am not going to monitor & tell who-ever that their transmission is not standard.
Thanks John
 
INTERESTING!! The closest automated system I have found is Port Townsend 0S9 where you key 3 times & it will give you ATIS.
One can get an idea of field strength by how far out when keying for ATIS.
I do not know of any Superawos out here in the Pacific Northwest = Seattle area.
I can imagine that unit is $$$$$, something our grass-roots airfield Board of Directors will not fund.
I had worked up a LED VASI for a 1/4ly meeting & was shoot down by non-night flyers. We have tall trees at both ends with narrow slot between them & I felt a 2 axis VASI would be a great safety issue. I still fly at night, but land long with a steeper approach angle, planning on 4th or 5th runway light to touch down at, 1,000' of runway behind me, on a 2,500' runway.
I'll check your link & present it to the B of D, but do not hold out hope.
I do not have many years left flying or owning a plane with this ADS-B out being forced on me. The thought of spending $5K to have it installed, yes I hold an A&P, but I can not install the unit in a Factory built airplane = per FAA @ NWATShow last weekend. Hard to justify the cost since my 1956 C-172 cost me $7,200 when I bought it...... in Oct 1986... The price of Fuel & an AI to sign off my 100Hr Inspection into an annual & that $500 insurance bill, to fly about 40 hours a year is getting hard to do on SSIncome...... John
 
GeorgeC said:
I've been to fields where you, if you key the mic on CTAF just so, you can say "bugsmasher 123ab radio check", it records your transmission and transmits it back to you, so you can hear how you sound.

http://www.superawos.com/perfect_radio_check_every_time.htm
Click to expand...
That sounds a lot more useful than a display of signal strength and modulation depth. The most common sources of poor transmit quality are the microphone and/or a cheap intercom or overmodulation. It might be possible to build something with a limited spectrum analysis capability to measure the width of the sidebands but I think it would be a pretty complicated project and anything less isn't likely to provide useful information.
 
I was hoping to get this directed to Jim Weir, who has his AERO'lectrics in the Kitplanes , since his writ up says to visit this site.

I have a challenge for you.

I live at an Airpark & monitor our frequency (122.80mc) & see a need to place at our run-up pad an indicator for our pad. I hear on my radio Aircraft transmissions that are not understandable, either from under modulation or over modulation. In simplex communications, you & I know that we do not hear what we transmit or sound like to the others on frequency.

So what I am asking is for you to up date this old old schematic to the digital world, a LED bar read out digital world.

I had an schematic here but it would not copy in... do not know how to place it in here.

I found this searching the internet. But it is OLD, as you may notice CK722 & 1N34 & copper oxide rectifiers, using a 22.5 volt DC supply is a bit newer than a cats-whisker crystal set.
It needs to be redesign for 122.8 mc, the meters need to be 10 step bar-graph read outs (LM3914).
AND if possible to be solar powered with battery back-up.

Are you up to the task??

If this sounds vaguely familiar, I have asked for this before & gone through different E-mail addresses to get the request to you for your consideration.

I am also getting OLD. Been in electronics for 60+ years & like LM324s too.
John @ 8W5 FCC 1stRT, FAA PVT-SEL A&P, 1956 C-172 owner-PIC
 
I just found Jim at an other site & sent him my challenge/request.
Thanks John
 
GeorgeC said:
@weirdjim, white courtesy phone...
Click to expand...
White courtesy phone, roger. Another Kitplanes column. We will have one at our airport in two or three months to see how well it works. Solar powered, 5 watt BRILLIANT Led display. I'm going to have fun with this one.

I wish I could use the transistors that this guy used in the original, but they are going for a couple of hundred bucks apiece as museum parts. I used one back in 1952 and if you looked at it crossly, it blew up. Germanium transistors, lord save us.

Jim
 
An LED bar graph set up "VU meter" style isn't going to give the pilot any feedback at all about the quality of their audio and/or presence of distortion.

Some will just yell into their mics to get the little bar graph to light up, like they're whacking the thing at the state fair with a hammer, to ring the bell and get their prize.

If someone's radio sounds so bad you think it's a safety issue, just tell them.

I laughed at the idea of dragging out a Cushman and giving hard number strength and modulation reports to pilots, though. That'd be a funny exercise in annoying the crap out of everyone.

I'd drag out the IFR or the Motorola for that job, myself. The Cushman is probably hitting the age where moving it off the bench is going to cause failures. Heh.

Uncontrolled airport. No requirement for radios at all. Some dude reading me modulation numbers off his service monitor over the air, and all that happened was the mic boom fell down away from my face when I whacked it putting the iPad in the side mount. LOL.

I'd say thanks and move the mic back where it belongs, but I can see dummies cupping the mic and hollering into it, "That better?!!!" Or just politely ignoring you or worse, giving you the virtual finger. LOL.

Bar graphs. Seriously? LOL. No. I'd use that for a joke... maybe sing some karaoke to it. Tell a passenger that it's a "beat box meter" and if they can peg it, they get a coke on me. Hahaha. "If you sing a perfect C, three bars will light up. Try it!" Hahaha. "That's a meter that tells us how angry the TRACON controllers are over at XXX Big Airport. When I make our taxi call, would you let me know how high it goes? I want to know but I'll be looking this way over here for traffic, so if you can help me out, that'd be cool... click, Podunk Traffic, Cessna 79M taxing to runway XX via Y.... click... how high did it go?"

I see nothing good coming of this. Hahaha.
 
I am glad that the Denverpilot got a good laugh out of this.
Send me the $$$$ for the unit you believe would work the Best. I'll get it installed.
Since I am on SSI & have minimal funds to waist, I felt that a display with IDIOT LIGHTS would be the least expensive & most likely I have the componetsl. Lets face it, a VASI is nothing more that a group of idiot lights too, & so are many indicators in other vehicles. So I feel good that pilots & airplane drivers can read idiot lights with ease.
I'll save my $$$ for the $6/gallon AV-Gas...
Being retired for 18 years, my test bench is a bit old, but works, with the only co$t is electricity to run it. Kinda like my 61 year old Cessna, that passed 100 Hr & annuals inspections with next to nothing wrong, just lube her.
I do wish to thank you for your constructive criticism that maintains the public thought that GA flying is for "Fat Cats" & not for the pilots that have the ability with minimal funds. That is one of the factors that have contributed to the fall of GA.
John a grass roots flyer, still enjoying it.
 
weirdjim said:
White courtesy phone, roger. Another Kitplanes column. We will have one at our airport in two or three months to see how well it works. Solar powered, 5 watt BRILLIANT Led display. I'm going to have fun with this one.

I wish I could use the transistors that this guy used in the original, but they are going for a couple of hundred bucks apiece as museum parts. I used one back in 1952 and if you looked at it crossly, it blew up. Germanium transistors, lord save us.

Jim
Click to expand...

Jim,
I still have a fair selection of Ge transistors US & Japanese made + many peanut tubes with docs too....
You are one of the last techs that designs & builds at the discreet component level.
I appreciate that & like reading your AEROlectrics column.
1952 is about when I got started in electronics with a cat's whisker crystal set & an older brother that would not memorize the resistor color code. In 1961, I was given 13 old B&W TV sets not working, my dad had a fit, I was able to get 6 of them to work by mixing parts from the goners & had to make a capacitor tester & MV for those electrolytics that dried out. Popular Electronics & other articles to get my self taught knowledge on a subject I liked to tinker in. Sure came handy when I went into the Navy (calibration Lab) & worked @ GTE in Equipment Repair Service for 26+ years. I am still repairing the "Old Stuff".... Know anyone that needs a CRT Beam Builder?
John
 
SuperUnicom/SuperAwos are autonomous radio/weahter reporters. One feature they've had for decades is the ability to do a self-radio check by playing back the last few seconds of what they hear. Not fool proof but it gives you a good guess.

Of course, there's the guy on the busy unicom frequency that spends minutes calling the FBO on each radio before moving. I just answer loud and clear and let the frequency go to more pressing traffic.
 
Flyingron,
Yes, that would be nice to have on our field.
Although 8W5 is a public use but privately owned, by 41 family/members of APOIA, we get NO, ZERO, in any sort of government help to fund such a device as a SuperUnicom. In fact we all pay more in property taxes to have the privilege to live on an airport that gets no help = thank you Kitsap County & State of Washington. I would be willing to fork-out $200 for this unit, but I believe that I would be the only APOIA member to do so.
This is a grass roots airfield, where most of the flyers are retired, low income, with the abilities to build & fly aircraft within the FARs.
I am currently fighting this ADS-B OUT requirement, writing Fed Reps & AOPA & anyone that will listen to reason, to drop the 30 nm vail within the FAR 91.225. For the simple reason; that all aircraft under the 30 nm vail, have a transponder with Mode "C" to be based there (8 airfields are under the 30 nm vail & do not have class B nor C airspace above them about KSEA, that this would help). To have accuracy that this ADS-B out would give for aircraft outside the class B & C airspaces is like requiring pie (3.14) to be taken out to the last digital decimal number in order to use it. Also interesting issue that came up at my EAA 406 was that drones maybe required to have ADS-B out on them. Where this with current technology is not far-fetched in the lease, just look at cell phones with GPS chip in them. Thus the drone ADS-B out would be very small with low battery drain & CHEAP from the mass production of it. This would give the FAA the "WHO IS FLYING THAT DRONE" that they want to have.
Time will tell, & maybe it is time to hangar-up my flying (1966-2020), for I'll be damned if I'll pay $5K to have an avionics shop install this ADS-B out in my 1956 C-172 that I bought for $7,200 & only fly about 40 hours a year.
Thank you for the come back. I'll put that on my dream list / nice to have. John
 
You must log in or register to reply here.
Back
Top