Ghost help  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       

All Forums >> RC Airplanes >> Vintage & Antique RC >> Ghost help
Page: [1] 2   next >   >>  

Login
Message << Older Topic   Newer Topic >>
Ghost help - 4/29/2008 2:57:39 PM   
sotonflyer


 

Posts: 31
Joined: 12/30/2002
From: Southampton, UNITED KINGDOM
Status: offline
Hi, well I got a Rand LR3 actuator (the one with the Rand-Pak, works off 3.6 volts) plus a Controlaire ghost TX and Ace superhet receiver (it looks like a later version) from Ebay. I also have a MacGregor ghost TX (from the late 1960's). Everthing works - the Rand centres OK although I get more rudder throw with the MacGregor and more up elevator with the Controlaire. The Macgregor is a neat unit, is in better nick and is well built so I might go with that at first. However, I am only getting 50 - 60 ft range with each transmitter with the aerial collapsed. The electronics of the MacGregor look similar to the Controlaire apart from the MacGregor has a based loaded aerial. Does anyone know the aerial length for the Ace? It looks a bit short and I get more range with about 30 inches of wire.

Now, I want to tune this up, improve the range and get it into a model, probably a glider/slope soarer of light weight so I don't need the throttle part of the Rand which has the usual crack (I will fix this anyway for future use). I know that Jaymen has written a lot of stuff on these systems but I am not an electronics person (although I can tell a transistor form a resistor). How easy is it to tune these systems? Do I need any special equipment? Can anyone provide some advice in easy to understand language?

I have a few single channel flying models with rubber driven escapements. One of which is a Minnie Mambo that I bought from Early RC. Is Boberos part of Easy RC? I think that the Rand, Controlaire TX and Ace RX was sold by his father! But I might be wrong. Hope someone can help. I can post pictures if required.

Peter

< Message edited by sotonflyer -- 4/29/2008 2:59:27 PM >
       Post #: 1

RE: Ghost help - 4/29/2008 3:24:22 PM   
sotonflyer


 

Posts: 31
Joined: 12/30/2002
From: Southampton, UNITED KINGDOM
Status: offline

PS - I meant BobHH and NOT Boberos. These handles are confusing!

(in reply to sotonflyer)
       Post #: 2

RE: Ghost help - 4/29/2008 6:06:16 PM   
ggeezer


 

Posts: 24
Joined: 4/8/2008
From: Saskatoon, SK, CANADA
Status: offline
Peter,
Could you post a photo of the receiver so that I can identify the unit. I restore these old sets and I used to service these radios in the 60s and 70s so tuning superhets is a specialty of mine. I most likely have the same setup you just bought.

Orv.

(in reply to sotonflyer)
       Post #: 3

RE: Ghost help - 4/29/2008 7:45:33 PM   
sotonflyer


 

Posts: 31
Joined: 12/30/2002
From: Southampton, UNITED KINGDOM
Status: offline
Hello Orv,

Not sure how to post pics but this might work...

http://www.rcuniverse.com/gallery/galleryitemSolo.cfm?itemid=140206

Many thanks,

Peter

(in reply to ggeezer)
       Post #: 4

RE: Ghost help - 4/29/2008 8:15:01 PM   
ggeezer


 

Posts: 24
Joined: 4/8/2008
From: Saskatoon, SK, CANADA
Status: offline
Hello Peter,
That rec. looks familiar. I used to be an Ace R/C dealer back in the good old days and still have a lot of the documentation. I will dig through the archives to see what I can find. If memory serves me, I think the rec. antenna length was stated at 24" but I will have to check. In most cases the length wasn't so critical that the input inductor couldn't be adjusted to match the impedance.
Does your Controlaire Tx. have a wire protruding slightly out of a rubber grommet on the back of the case?

Orv.

(in reply to sotonflyer)
       Post #: 5

RE: Ghost help - 4/29/2008 9:12:05 PM   
sotonflyer


 

Posts: 31
Joined: 12/30/2002
From: Southampton, UNITED KINGDOM
Status: offline

There is NO wire protruding out of the back of the case. My Controlaire GG Tx is version 2 and has 7 transistors.

Peter

(in reply to ggeezer)
       Post #: 6

RE: Ghost help - 4/29/2008 10:38:26 PM   
jaymen


 

Posts: 204
Joined: 3/26/2003
From: Mission Viejo, CA, USA
Status: offline
You have an Ace Pulse Commander receiver, 27 mHz.
The Ace supehets have no AGC. They mostly came set-up for 2.4 volts, as used with the Pulse Commander transmitter, and Adams Actuator. There are two resistors in the IF biasing that can be increased in value for 3.0 volts, and 3.6 volts respectively, The receiver oppration will be erratic and un-tunable if they are not the right value for the voltage applied. Your particular version has a bridge output for a non centertapped Adams actuator and is the last, most recent version. The output stage can directly drive a magnetic actuator but is not powerful enough to drive a 3.6V Mitsumi motor as used in the LR-3 for very long without overheating the transistors. I actually bypass the 4 output transistors and tap in ahead of them to the driver stage and use that signal to drive the Rand's integral switcher.

Anyway, tuning can be accomplished using a current meter in line with the Rx. battery supply, no actuator connected to Rx. The transmitter needs to be turned on, the antenna collapsed, and the tone full on(hi throttle). DONOT OPPERATE TX WITH NO ANTENNA, you will burn out the output transistor!!

The receiver's idle current( Tx. off) should be less than about 20ma. With the Tx on the current should rise to around 30-50ma or so. Slowly back away with the transmitter until the receiver current drops to close to minimum idle current. If the idle current was 15ma, then about 20 ma would be good. At this point, tune the antenna slug for peak current on the meter. If the meter peaks out, try moving the Tx further away and re-tune the coil for peak again. You can then do a range test to see if the receiver's range is improved. Only tune the IF coils if the range is still poor. Tuning is done the same way, starting with the yellow, then white, and finally the black if coil. Peak each coil on the meter, and keep moving the Tx away to get the current to drop on the meter so it won't peg out as you tune each sucessive coil's slug.


I will look and see what the resistor values should be for 3.6 volts, but it is annotated on the Ace receiver schematics I have attached here. Also note this schematic shows none of the output transistors, it shows a PNP output xsistor for driving a relay, THIS IS WHERE YOU TAP IN FOR DRIVING THE LR-3 W/ SWITCHER. The relay is not used, the connection instead goes to the Rand's switcher.


One reason Ace gives no tuning instructions for the IF is because it is tricky with no scope, and their Tx. (Pulse Commander) has no switch for tone on(motor Hi) to use when tuning. Additionally, with no AGC, one must be sure to keep moving the Tx further away as each coil is tuned and peaked to insure a low signal level at the receiver when tuning so it won't start "clipping" the signal. You can see this with a scope, but the ammeter will only show a high current reading and not move when you tune the coil slugs, this means the transmitter is too close.

If you still have poor range, it is most likely the Tx has low output. I have re-tuned quite a few, that were significantly down on power. One can attribute this to components drifting with age. On Controlaire transmitters with output meters, you should get at least a reading of 9 on the meter with the Tx on, antenna extended, and about 7 on the meter antenna collapsed. I use a scope to look at the RF envelope when tuning, but one could use a ammeter inline with the suppy, or a field strength meter. Once the Tx output is verified as good(about 350milliwatts) then a comparison of other Txs can be made using a field strength meter.

Attachments
Click to see fullsize image.
Click for fullsize


< Message edited by jaymen -- 4/29/2008 11:12:02 PM >


_____________________________

Did you charge the transitory remitter batteries ?

(in reply to sotonflyer)
       Post #: 7

RE: Ghost help - 4/30/2008 12:26:12 AM   
ggeezer


 

Posts: 24
Joined: 4/8/2008
From: Saskatoon, SK, CANADA
Status: offline
Wow! Jayman just saved me a bunch of hunting and typing.
The only other thing I would do before starting to tune the IF cans is to take a felt marker and mark the existing positions on the can and remember to only tweak the slugs just a little bit as the setting can be quite sensitive. If you get them too far off, especially all three, it is almost impossible to juggle them back without more specialized test equipment. That is why I always mark the initial settings before attempting to tune them because it is now easy to go back and start again.
I can't think of the number of rec. I used to get where the owners would try to tune the IFs and put them completely out of whack.
Also, use a plastic tuning wand or a sharpened wooden dowel as a metal screwdriver will change the inductance and make tuning impossible.

Orv.

(in reply to jaymen)
       Post #: 8

RE: Ghost help - 4/30/2008 5:06:59 AM   
jaymen


 

Posts: 204
Joined: 3/26/2003
From: Mission Viejo, CA, USA
Status: offline
Orv is sure right, because if they get way out, you are lost without a scope. I actually use a Hewlett Packard synthesized RF signal generator, set for AM 100% modulation @ 1000Hz to check the tuning and sweep to check bandwidth, then I check sensitivity.

My Min-X, Controlaire, Citizen-ship, Hallco, and Ace pulse sets all have about 5 microvolt sensitivity, give or take, and all have about 200-300 feet of ground range with the Tx antenna collapsed. This is a good guideline or those who lack more sophisticated test equipment.

It is still possible to do it the way I described in the previouse post above though, with care, and I did forget to mention using non- metallic tuning wands/tools, Thanks Orv.


Speaking of simple test equipment, I use a field strength meter that is set to read full scale, which is ten, when connected to a known 350 milliwatt source. From this I can closely estimate other transmitter's output power, meaning if it read 7.5, then that would be about half, or 175 milliwatts. Another clue to proper output is that the final transistor is usually warm.


Another old school tip: ( no pun intended) Use the point of your soldering iron to gently warm the tuning slugs and melt the wax if there is any, otherwize you will crack the slug trying to turn it. The antenna coil slug is the most prone to move under vibration and is often waxed after adjustment as a precaution. Re warming of the wax to melt it, or another drop of wax from a candle after final range check is advised. For gliders, this is not so critical.

A real crude method is to mark the coil slug positions, and while moving away from the transmitter note the point where opperation of the Rand becomes a little erratic. Then try tuning the slugs a little one way or the other, only a 1/16th of a turn to see if that improves reception as noted by how well the LR-3 or actuator is tracking the pulses. Start with the antenna coil, then move on to the yellow, white, and black IF cans, each time only moving them slightly to see if opperation/range can be improved. If at any time you loose signal and the Rand cycles, return the slug to where it was marked and move closer to the transmitter until steady opperation resumes, then try again. The problem most guys have is they start turning the slig to far one way or the other and loose track of where they started. The key is to discipline yourself to only turn a the slug a tiny bit and note which direction you turned it.
I once had a receiver that could only be tuned in this way, it was a superegen though. In the old days, that was how most of us did it unless you had the luxery of a microammeter, they were expensive!

Use the LR-3 throttle arm for flaps or spoilers!

_____________________________

Did you charge the transitory remitter batteries ?

(in reply to ggeezer)
       Post #: 9

RE: Ghost help - 4/30/2008 11:13:34 AM   
sotonflyer


 

Posts: 31
Joined: 12/30/2002
From: Southampton, UNITED KINGDOM
Status: offline

Hmmm... interesting stuff and thanks for the help so far.

The Ace Rec. came to me wired to the Rand with 3 NiCad's to give 3.6 volts. The Ace was wired to the Rand Pak as per Rand instructions and I assume that it is using the Rand's internal switcher. At any rate it seems to work fine (the Rand is switching correctly) with this setup and on 3.6 volts. However, I better stop using 3.6 volts and see if I can replace the resistors as suggested. I hope that I can locate the correct ones! Will have a good look tonight when I am home form work. I also get better range using a 30 inch aerial on the receiver instead of 24 inch.

I have quite a number of other superhet single channel receivers. Most are MacGregor (with and without relay), Futaba and OS. I have used the MacGregor's in a couple of my single channel models. They give a similar range (aerial collapsed) as my ghost system and as these models are small 500ft in the air is about as far as you want to get. I would also want to put the ghost system in a small-ish model so I guess I could get away with relatively short range. However, I still want to get the best out of it for ovbious reason's.

I could use one of the MacGregor relayless receivers. These are similar to the Futaba single channel Rec. in that they use a 9 volt supply and then have a simple transistor switch (is this the correct term?) to drive an escapement using a second battery (usually 3 volts). I am not sure if this transistor switch could cope with 3.6 volts plus the Rand motor. For motorised actuators MacGregor suggest using a relay Rx. I have tried using one of the MacGregor replay receivers with the rand and I get a similar range. All this leads me to think that it'll be best to use the Ace receiver for my ghost setup.

For range it sounds like it'll be best for me to look at the transmitters first and see if I can improve these and use the one that gives best results. At the moment thay are equal as far as range goes.

I plan to put the ghost system in a period (late 1960's) slope soarer. I could use the Rand throttle arm for spoilers or flaps but then this would not be in keeping with the design. At any rate, I like to keep it simple at leat at first! I want to have this ready (plus my current single channel gliders) for a slope nostalgia event in the middle of September. Here in the UK there isn't much interest in flying these old systems, although there are collectors that just put them on display, a waste I think. Nostalgia normally means late 70's to 80's models + proportional. Any flying single channel or ghost system will blow them away!

(in reply to jaymen)
       Post #: 10

RE: Ghost help - 4/30/2008 8:09:34 PM   
ggeezer


 

Posts: 24
Joined: 4/8/2008
From: Saskatoon, SK, CANADA
Status: offline
Jay,
It sounds like you have some really good equipment in your shop. As a young man starting out in life with very little money (early 60s) for luxuries like oscilloscopes and vacuum tube volt meters etc., I used a simple low cost, very high impedance crystal earphone to service and tune both regen. and superhet equipment. By connecting it to subsequent stages in the circuit and listening to the tone, I could analyze problems and peak tune the stages. It is amazing how accurate and sensitive the ear is to subtle changes. In fact, I still find this a useful method and still have that original earphone.

Orv.

(in reply to jaymen)
       Post #: 11

RE: Ghost help - 4/30/2008 9:09:08 PM   
jaymen


 

Posts: 204
Joined: 3/26/2003
From: Mission Viejo, CA, USA
Status: offline
Orv, back in the old days, when we all needed it the most, I had no test equipment, and even less knowledge!

Here is a funny story about my first Controlaire Galloping Ghost system:

I had read the MAN article about Butch, (Art Schroeder's kid) and the Mayfly by Meyers Models, basically an ARF for .049 Cox and the Rand LR-3. I had never seen a pulse system in opperation, as out here on the West Coast (California) they were not popular, and besides, this was Orbit, Kraft, Bonner, Micro Avionics, and PCS's backyard, everyone had Digital Proportional rigs. The only other "old school " stuff I had seen at that time was escapements, and reeds. So when I saw a used Controlaire Galloping Ghost at the hobby shop, they kind of looked at me like I was crazy to even be interested in it. But, it was only $50.00 and it had a Bonner Digimite stick, so in my mind it was the cheapest proportional rig around at that time. I could not figure out how one servo gave all three functions, but since I did not have the money to buy it, I did not ask for them to fire it up and show me that it worked.

Anyway, I must have gotten a ride up to the hobby shop with my grandfather, who often took me there, because somehow my family found out or got wind of the fact that I was enamored with getting this Galloping Ghost radio ( even though I knew I could never afford it). Before long, the radio sold, dashing my dreams of getting a proportional radio. I had a Junior Falcon with a Bonner Vari-Comp, and the Rand LR-3 equipped Controlaire seemed like an ideal improvement for it.

Anyway, that year for Christmass there was a funny brown paper bag under the tree from "Santa" which means in my family it was a gift from everyone. Nobody seemed to notice it, and finally my dad asked me who it was for, well I looked and it said "To Jay From Santa". Much to my surprize, there was the Controlaire, with the F&M Vanguard and Rand LR-3, wow, they got it for me!

My uncle Bob was there, an electronics guru, and so we fired it up. Instantly the Rand LR-3 went into pulsing and wiggling away, which really confused me, and about the only thing that did make sense was the throttle arm did respond to the toggle switch and stayed put, but everything else was gyrating away. It made no sense to me, or my uncle, niether of us had no clue as to how pulse proportional was supposed to work. My uncle suggested we try a range check after I opened the receiver and saw the tuning coils, I asked him if he could maybe adjust it to stop the pulsing/wiggling. Instead, we went and range tested it, and he determined it was receiving signal, but there must be some problem in the transmitter sending intermittant signals( pulsing maybe?) and that we should get it checked out.

I was really let down, here a $50.00 used radio was a piece of junk, I should never had thought you could buy anything good for that cheap. We looked inside the little box the airborne had been in and found a repair/service receipt from "Larson Electronics" on S. Grand St. in Santa Ana, only a few miles from where we lived. It said the radio had been tuned and tested only a couple weeks ago.
So, after Christmass, I took the Ghost over there in the basket on the front of my bike. I think Gordon Larson and Bob Novak nearly died laughing when I explained the radio would not stop wiggling! Gordon took the radio into his lab, while Bob gave me a tour of the radio factory where they were making RS Systems radios. Then, after the tour, Gordon briefly explained how pulse proportional/galloping ghost works and I humbly went home with my radio!

This single event let to lifetime fascination with Galloping Ghost systems.
I never did fly that radio, it just seemed to weird to ever be capable of working correctly, and I built a World Engine Blue Max kit proportional unit for my first R/C plane. I still have the Controlaire too.

< Message edited by jaymen -- 4/30/2008 9:50:04 PM >


_____________________________

Did you charge the transitory remitter batteries ?

(in reply to ggeezer)
       Post #: 12

RE: Ghost help - 5/1/2008 1:11:33 AM   
boberos


 

Posts: 426
Joined: 4/22/2005
From: peterborough, ON, CANADA
Status: offline
Hi Soton,
I have no commercial interest with anyone, but I do know BobHH.
For some unknown reason, I do have an interest in these old radios.
Best of luck with your GG equipment.

Jaymen, thanks for your articles & tuning tips.
You are a great source of info about these mysterious wiggling things. Now I understand why.
A lot of those old transmitteres seem weak these days.
But that is life.

Best to all,
Bob

(in reply to jaymen)
       Post #: 13

RE: Ghost help - 5/1/2008 2:53:10 AM   
BobHH