Weird HF Antenna - SunAir

[aseanaero]

I bought an old Piper Aztec for parts salvage last week and it has a very unusual HF antenna

It's a SunAir Electronics reel system that uses a small electric winch to feed a copper antenna through a 'stinger' in the base of the fuselage.

Other components are a large antenna coupler box and a reel control system in the cockpit to tell you how many feet of antenna is delpoyed.

I've NEVER seen one in 25 years of being around aircraft , anyone seen one before ?

http://www.asean-aerospace.com/aviation_photos/100_8871.JPG

Antenna reel/winch

http://www.asean-aerospace.com/aviation_photos/100_8882.JPG

Reel system controller

http://www.asean-aerospace.com/aviation_photos/100_8872.JPG

Antenna coupler

[the wizard of auz]

Jeez.... that makes my old 25kg Sunair HF look positively modern. I know mine is a 1969 model, so thats either a flash version or older. :eek:

[aseanaero]

Wiz

That is just the antenna coupler !

The SunAir boat anchor HF is another 2 boxes in the nose compartment plus the HF controller in the cockpit.

[the wizard of auz]

Yeah. I have the two boxes in the nose and the brick in the dash as well.
Lucky the C310 has a decent sized nose compartment. :ok:
She's old but I love her. It was my first ever airplane. :}
one day when I win Lotto, I'll do the big restore on her. historical value. :E

[mendi63]

On the end of the wire should be a drogue (a plastic funnel made a good one). They were often left wound around the perimeter fence when the pilot forgot to wind the antenna back in.:ugh:

[aseanaero]

On the end of the wire should be a drogue (a plastic funnel made a good one). They were often left wound around the perimeter fence when the pilot forgot to wind the antenna back in.:ugh:

The drogue is gone and so is the stainless steel extension in the stinger.

Apparently the stainless steel tube got stolen off the aircraft in Irian Jaya , thoughts were it would make a really good blow gun :bored:

[tail wheel]

That wind out HF antenna is probably more efficient, particularly at lower frequencies, than more modern electronically tuned HF antennas.

As Mendi63 noted, in the days of DC3's etc, the antenna wire was a regular feature of airport fences!

Sunair HFs were notorious for noise. It can't be too old - I think Australia converted from AM to SSB in the early 1970's? Or is that Sunair HF multi function AM and SSB?

[troppo]

If it got flogged irian jaya it could well be a penis gourd by now...or a bong.

[aseanaero]

That wind out HF antenna is probably more efficient, particularly at lower frequencies, than more modern electronically tuned HF antennas.

I've only read about trailing HF antenna on old WW2 aircraft like Catalinas , never seen one on a GA aircraft.

Whether it's AM and SSB don't know yet , I haven't looked , let you know later.

[bushy]

The first flying job I ever had was flying cherokee sixes out of Port Augusta, one of which was an RFDS aeroplane. The base director insisted that it be fitted with a trailing antenna much like the one in the AZTEC. I think we had to keep running it out until the load meter peaked??? It was also fitted with a fixed antenna,and once it was tested, and everyone had a play with it no-one used it any more. Everyone used the fixed antenna.
Theoretically it is much better than the fixed antenna. We used HF most of the time.

[Checkboard]

Ernest K. Gann's Fate is the Hunter (http://www.amazon.co.uk/Fate-Hunter-Ernest-K-Gann/dp/0671636030/ref=sr_1_1?ie=UTF8&s=books&qid=1235819915&sr=8-1) describes a scene in which he is delivering a DC3 to Europe, and in order to let down through cloud over the sea, he lets out the HF antennae, and descends until the antennae hit the water!

You can see the antenna is still useful, even if the radio doesn't work anymore!

[Led Zep]

Highly effective at taking out runway lighting too. :\

[Capt Fathom]

Yep.

Flown a C175 and an Aztec with those antennas!

The one on the C175 was electric..:uhoh:

The one on the Aztec was manual. You had to count the number of turns on the way out, so you knew when you got it all back!

[aseanaero]

The one on the C175 was electric..http://static.pprune.org/images/smilies/worry.gif


This antenna is electric also

and in order to let down through cloud over the sea, he lets out the HF antennae, and descends until the antennae hit the water!


What ? I guess the antenna load changes or something when it hits the water ?

[Checkboard]

As I remember, the water knocks off the drogue, and the antennae starts whipping around. :}

[Brian Abraham]

Was a time when HF was the ONLY radio for GA (5 channel Skyranger?). Tower comms were HF at secondary airports. VHF was reserved for airlines and primary airports, GA not permitted at primary airports. Antenna either a clothes line strung from fuselage to tail to wing tip, or the reel as shown. 172 I flew had the clothes line and 180 the reel. Most GA was sans radio in those days, SARTIME being the modus operandi and an AIRFLASH PRIORITY phone call the means of cancellation.

[aseanaero]

Thanks Brian

I have an old filght service guy now charter operator coming to Jakarta from Oz next month so I'll ask him about the pre-VHF days for GA , probably explains his fascination with HF radio , he grew up with it !

I learnt to fly in the mid 80's and probably used the HF for real 2 dozen times.

[triadic]

I learnt to fly in the mid 80's and probably used the HF for real 2 dozen times.

You were lucky (!). I know many GA pilots that were never taught how to use the HF in the aircraft they flew until they day they went bush. For many it was just a gadget in the panel to be left off. Transponders were the same when they started to appear in GA aircraft. Turn it on - then what do you do ???

Great times and the HF trailing antenna was certainly not uncommon. As the electronic tuners got better then they slowly disappeared. Some of the larger GA aircraft started having Collins 618T's fitted which was an airline type HF and they were great. Just had to find a suitable location to fit it!!

The Secondary towers used 3023.5 if I remember correctly.

[aseanaero]

Some of the larger GA aircraft started having Collins 618T's fitted

I've sold a couple of 618T's in core condition for US$1,000 each which we salvaged out of a 727 VIP aircraft, working but needed a shop visit as the aircraft had been parked for 9 years.

They go for around $2,500 to $3,000 outright with a fresh tag in the US now.

You're right they are physically massive (90cm x 40 x 30cm from memory) and they weigh 25-26kg but probably no heavier than a complete older SunAir HF set.

Collins Proline gear out of 727 and 737 classics is going for peanuts in Asia at the moment as there were a lot of older aircraft that came here from the USA (some from the Mojave aircraft storage facility) and operated for a few years until they hit a C check and are now being broken up for salvage

[Capt Fathom]

And who can recall the old VHF's that had to be tuned-in.

[aseanaero]

http://www.asean-aerospace.com/aviation_photos/100_8886.JPG

Here's a bit of vintage aircraft radio porn ...

This 'buck rogers' mike weighs about 1kg and is steel , if it got loose in turbulence it would make a nice dent in your skull.

[Tmbstory]

Aseanaero:

Re your post No:1 28th February, I once had an experience of a similar system in a Cessna 310. It was in November 1965 and we were testing Survey equipment, a "bomb shaped" device to measure the magnetic field over a particular portion of land.
The extending and winding in of the device was quite similar to your antenna. After a test we found that we could not retract the "bomb" and we could not jettison it , so after much discussion with the Tower in Sydney, which included an option to try and drag it off on the water of Botany Bay or try and "land" it on the runway at the Airport.

The feeling was that the "bomb" may skip off the runway and wrap itself over the the tail plane with a resulting big problem. They filmed the landing and there was no drama. the "bomb" flew gently onto the runway, wore off about half an inch of one of the fins, the wheels of the aircraft then touched down and the emergency ended . The Airport then re-opened and the engineers got into the system and fixed it. The reel system had broken and jammed between the cockpit floor and the bottom of the aircraft.

Regards

Tmb

[Tmbstory]

Capt. Fathom:

Sure can! The Industry has made some improvments over the years.

Rgds

Tmb

[aseanaero]

Tmbstory , I guess that's why this reel system isn't so popular anymore , one more thing to go wrong , snag on a fence or hit a high tension power line with.

I would have thought that for ultra long range HF the trailing antenna would have given better performance ?

[forget]

STR 9X, 10 Channel VHF. Believe it or not, in the early '60s, this is what the Vulcan force carried. Plus an 18 (?) channel HF.

R1475 (http://www.vmarsmanuals.co.uk/new/str9x.htm)

[Peter Fanelli]

The Boeing E4 has a trailing antenna for VLF transmission.


The lower trailing wire antenna area contains the aircraft's 5 mile long trailing wire antenna reel, the antenna operator's station as well as the antenna reel controls and indicators.

[Norman Wear]

Do you still have that old SunAir reel system and control heard?

Looking for a system to work with Ham radio on AC

Tnx

[aroa]

I had one of those in an old Auster.... and a box of crystals.
Before heading off to the next place had to plug in the appropriate xstals for the destination... and on the way, press to transmit and wind a handle for max on the needle gauge. Fizzed out along the trail somewhere, eventually.
Back in Oz I was told not allowed! so I had to install an AWA Skyphone.

How electronics has evolved..!:ok:

[asw28-866]

...- .... ..-. ? -. . ...- . .-. -.-. .- - -.-. .... --- -.!

[bankrunner]

I would have thought that for ultra long range HF the trailing antenna would have given better performance ?

Yep, especially with the really poor performance (and exceptionally high cost) of early autotuners, and that you're pretty limited to what can otherwise be attached to a small aircraft. Most antenna designs on light aircraft are rather inefficient.

Getting the antenna snagged on fences was probably a bit of a killer though; wonder how much the local avionics bloke charged every time someone did that? :E

For 3452KHz you'd ideally want about 21m of wire (quarter of a wavelength.)

[tolakuma manki]

@asw28-866
.-- .... -.-- -. --- - ?

[ampclamp]

The old reel up wire antenna would work well given you could actually get a length out that would be resonant. Not used one but saw them a long time ago.

Cant remember who asked but I have some plug in crystals from a very old VHF set. Choose your freq then plug and play. You can open up the can and see the crystal between the contacts. Nice.

vhf never catch on, why not
.. -. / .-- .... .- - / .-. . --. .- .-. -.. ..--..

[The Wawa Zone]

I knew one dodgy character who replaced a winch / reel assembly with a different one which didn't fit - until he sawed, planed and varnished a nice wooden block to mount it on the rear fuse floor. All was good until he had a lightning strike and the carpentry work caught fire.

This looks pretty modern to me - who's ever used an ADF with a hand crank tuning knob and a meter ? (No not the hand cranked antenna :8 )

[asw28-866]

@tolakuma manki

Just a weak joke at all this historic radio stuff, and yes I was bored!

'866

[ampclamp]

Worked on an old deHav Dove with a hand crank ADF with a Bowden type drive down to the loop from memory. Long time ago.

[Frank Arouet]

Brian A;

AIRFLASH PRIORITY

Someone can and probably will correct me, but wasn't it an "AIRMOVE PRIORITY" free call?

I recall the "AIRFLASH", but can't remember what it was about.

The drouge was only a plastic childs drinking cup, usually blue for some reason. Heaps on fences as already mentioned and 5499 was the most used freq I used in the East. Stuck in my mind all this time for some reason. Morse was possibly a better means of communication. More reliable at least than the static over voice on these monsters.

Anyone remember the VAR?

[zac21]

Frank,
I remember well the free 'airflash priority calls' from public phones to cancel SAR when the Sunair HF was cactus. And I will never forget having dragged the 'drouge'(plastic funnel) after the antenae wire came off the reel and jambing it against the roof (C185A) That must have been between 1969 and 1976, long time ago now!!

[Ex FSO GRIFFO]

Last used the VAR at West Maitland around '66 / '67 or so....

FUN trying to get the 'Aural nodes' 'in line'....(East / West direction)

:ok:

[Ex FSO GRIFFO]

Hi Frank,

The 'memory cells' fading a little, however,

I seem to recall that the 'Airmove Priority' was for the exchange operator to be able to put through your SAR cancellation calls free of charge, on the first (next) available line,

Whilst the 'Airflash priority' was to enable (instruct) the operator to actually interrupt a call in progress to enable you to call in an URGENT event - like - ooops I've crashed, or observed a crash etc. and require assistance......

Others may be able to clarify further....

Cheers :ok:

[zac21]

Griffo,
I think you are right as we had phone party lines and calls had to be interupted to cancell SAR, hence the Airflash call.
Like I said, all a long time ago.