Chaparral Black Box...what is it?

[phlatwound]

I recently acquired some C-band odds and ends, including this critter here:



Has anyone seen one of these and know what it is? Looks like it might be a servo tester but I'm not sure.

 

[wallyhts]

I recently acquired some C-band odds and ends, including this critter here:

<img src="http://www.satelliteguys.us/attachment.php?attachmentid=87270"/>

Has anyone seen one of these and know what it is? Looks like it might be a servo tester but I'm not sure.

Look's like it will let you control the servo motor on a feedhorn.

You like to take things apart? If so would be cool to see the inside.

 

[phlatwound]

...If so would be cool to see the inside.

here ya go:



So nobody has seen one of these before?

 

[lost_mesa]

I used to have one of these. When Chaparral first came out with their polarotor, there weren't many receivers that supported them. (Before the polarotor, we used TV antenna rotors to changed polarity). This little box supplied the 5 volts and pulse to run the polarotor if your receiver didn't have that capability. It uses a 555 timer to generate the pulses. The switch is for changing polarity 90 degrees and works by changing the timing of the 555 chip. The pot fine tunes the timing and thus the polarity.

 

[Anole]

I think I have one. Somewhere.
Came in a care package when Linuxman took down his massive system and moved.
Didn't recall the name brand on it, though.
Sounds like museum material.

 

[SatelliteAV]

Had a box of these in the work truck for years. Wish I had even one of them now. The basic control design with the 555 IC was so simple on these units.

If anyone has one for sale, please PM me and we could work out an equipment trade or PayPal.

Working on a DiSEqC 1.2 Controller prototype with automatic skew control memorized by the saved position. Not happy with the current implementation and the project would benefit from reviewing an "old school" unit.

 

[phlatwound]

...please PM me...

You got mail.

 

[Magic Static]

SWEET!! :

 

[phlatwound]

I used to have one of these. When Chaparral first came out with their polarotor, there weren't many receivers that supported them. (Before the polarotor, we used TV antenna rotors to changed polarity). This little box supplied the 5 volts and pulse to run the polarotor if your receiver didn't have that capability. It uses a 555 timer to generate the pulses. The switch is for changing polarity 90 degrees and works by changing the timing of the 555 chip. The pot fine tunes the timing and thus the polarity.

Thanks lost mesa, I figured someone here had seen and used one of these.

...Sounds like museum material.

Not so fast there oh Green one!

 

[SatelliteAV]

Well, call me a museum!

Phlatwound and Anole have been so kind! Each have offered a unit for testing. Thanks to both of you!

Phlatwound will be sending the unit for my testing! :

 

[truckracer]

We need the schematic and parts list so we can build this and use our polo rotors with fta receivers without an analog receiver.

 

[FaT Air]

http://www.hvlabs.com/555servo.html

 

[turbosat]

I built something like that years ago for use with the first feedhorn I had, on the first big dish I had. Polorotor I , the first type, would work fine with it, just reversing the direction with a little toggle switch. (old PR-Is would just spin in a complete circle). The later PR2s wouldn't work with it though, as they required feedback from the receiver. Just by-passing the feedback wire still wouldn't make it work right , if I remember correctly.

 

[wallyhts]

Had a box of these in the work truck for years. Wish I had even one of them now. The basic control design with the 555 IC was so simple on these units.

If anyone has one for sale, please PM me and we could work out an equipment trade or PayPal.

Working on a DiSEqC 1.2 Controller prototype with automatic skew control memorized by the saved position. Not happy with the current implementation and the project would benefit from reviewing an "old school" unit.

When you get it can you post more pics so we can see the traces on the pcb? Sounds like a fun easy project to make and I bet a lot of people have 555 timers sitting around.

Thanks

 

[wallyhts]

R1 1 820 Ohm 1/4W Resistor
R2 1 68K 1/4W Resistor
R3 1 10K 1/4W Resistor
R4 1 1K 1/4W Resistor
R5 1 1K Linear Taper Pot
C1 1 1uF 16V Electrolytic Capacitor
Q1 1 2N3904 NPN Transistor 2N2222, Most Small Signal Transistors
U1 1 555 Timer IC
MISC 1 Board, Wire, Knob For R1, 8 Pin Socket For U1

Source:http://www.aaroncake.net/circuits/servocon.asp

 

[Anole]

I have two units like Phlatwound showed in his photo.
The third has an additional toggle switch mounted below the knob.
My assumption is that changes between Vertical and Horizontal polarity.
That would add significantly utility beyond just using the device as a servo tester.


edit: a later Chaparral model of different design and packaging has a Quality Control sticker on the back side.
The date is either 1985 or 1988, I can't quite tell.
So that would suggest the ones made from old Pong controllers are even older.
.

 

[wallyhts]

I have two units like Phlatwound showed in his photo.
The third has an additional toggle switch mounted below the knob.
My assumption is that changes between Vertical and Horizontal polarity.
That would add significantly utility beyond just using the device as a servo tester.

edit: a later Chaparral model of different design and packaging has a Quality Control sticker on the back side.
The date is either 1985 or 1988, I can't quite tell.
So that would suggest the ones made from old Pong controllers are even older.
.

Lol pong...

Anyway u post pic?

 

[phlatwound]

...The third has an additional toggle switch mounted below the knob...

That must be like the one lost_mesa described earlier, I wondered what he was talking about since mine didn't have the switch.

...My assumption is that changes between Vertical and Horizontal polarity...

Are you saying that you think a switch flip will turn the probe 90 degrees?

 

[lost_mesa]

That must be like the one lost_mesa described earlier, I wondered what he was talking about since mine didn't have the switch.



Are you saying that you think a switch flip will turn the probe 90 degrees?

Yes, mine had a black toggle switch below the knob that flipped the polarity 90 degrees. I didn't notice until now that the one in the photo doesn't have this switch, as mine was otherwise identical, including the Condor branded wall wort. If I remember correctly, it switched in an additional resistor plus an internal trim pot to increase the pulse width. The internal trim pot was used to calibrate the 90 degree polarity flip.

The external knob fine tuned both polarities. I'd usually flip the toggle switch for the opposite polarity, turn the knob to null an analog video signal, then switch back to the correct polarity. The null is much sharper than peaking for maximum signal on the correct polarity. The design was very easy to reverse engineer. I home brewed a few back then.

 

[Anole]

Working on a DiSEqC 1.2 Controller prototype with automatic skew control memorized by the saved position.

A few years ago, when we were trying to talk Sadoun into adding servo control to his G-box, I put forth the idea that the box could easily remember independent servo positions to go with each satellite location.
Nothing ever came of it, and now the G-box 3000 seems to be out of production, too.

What never occurred to me was an independent diseqc 1.2 device that listened to BUD positioning commands, and provided the servo positions to match.
H/V voltage on the line would flip the servo controller between the two polarities.

At the time, it seemed a logical add-on feature to an existing box.
But a stand-alone could work.

Wonder what ya had on mind?
edit: don't tell me... a receiver feature?