Rocketry Planet

Arnold

Would you please provide some additional information that is not on your website?

1) What is the frequency used by the transmitter?
2) Can the frequency be changed by the user?
3) What it the rated power output of the transmitter?
4) What is the Receiver Sensitivity?
5) Is there a Security Coding or other method to prevent another unit or spurious transmission from activating my reciever?
6) How was the range capability of "Over 1 Mile Range" deterimined?
7) Is there a removeable safety interlock on the transmitter?

John

I saw this posted John:

General Specifications
Operating Temperature: -4° to +140° F (-20° to +60° C)
Receiver Type: Superheterodyne
Sensitivity: -118 dB (minimum)
Selectivity: 6 KHz
Carrier Frequency: 27,255 MHz
Number of Codes: 65,536
Code Setting Method: DIP switch programming
Antenna Impedance: 50 Ohms
Range Manufacturer specs 2 miles. SWT tested 1 mile city
Interlock Magnetic key

Shouldn't that be a period in the carrier frequency? (Or are they using the comma as the decimal place holder like some other places do?)

Thanks Art,
The information posted on the Space Warp website was after I posted my questions. The thing that concerns me the most is safety with any launch system. In this case, I did not see adequate information in the initial news article or the website. I still have many reservations considering the design.

1) The Magnetic interlock key is on the receiver. I readily agree that the reciever should have a safety shut off while any one is at the pad. However there should be an Interlock at the transmitting site as well.

2) The pad cables are 12' long. This is a remote system capable of launching High powered rockets (why else would I be interested in the posting on Rocketry Planet). This means that "as is" when a user arms the receiver with the Magnetic interlock, he is then 12' from what ever size HPR motor. (seems kind of wrong for a system that is $1499)

3) Why do many of the vendors in the hobby lead marketing statements "No Amateur Radio License Required". Ok if a Ham license is not required, then what is the FCC compliance of this system?

Say I wonder what the Booster Vision guys use for licensing or compliance? Oh wait there is a statement on the BoosterVision site that the receiver is a consumer use item and no license is required, FCC Certified. However the transmitters require a license. Well it would appear that BoosterVision is OK.

There are other Wireless launch systems available and I have similar "safety" concerns about their designs also. However this is a very expensive offering, the product quality and information should match the price. But you know, according to the manufacture this device is "Designed for the Serious Rocket Scientists" and "$h!t Happens"

John

Hi John,

I simply posted what I saw on the website, sorry; I was only posting as a public service

Our license free transmiters have an FCC-ID certification number.
We also sell license required units.

I have NO CONNECTION to Spacewarp.

My guess as of reading this again is 27.255 is one of the channels legal for use of remote control in the CB band, at least it was in the 70s when I fixed them as a kid with my FCC Radiotelephone permit.

I am assuming Spacewarp is using an FCC certified 27.255 transmiter since they make the license free claim.

As for other wireless systems, if you claim license free, you need an OEM unit that carries the certs along with it. Many OEMS have them for sale. One of my favorite for data circuits is Maxstream Radio moduals.

First I have no affiliation with any company involved or any potentially competing with the Space Warp unit. Since the range is intended to be up to a mile, one would assume it is intended for VERY LARGE motors/projects. Why wireless relay systems seem to be tricky is beyond me, but almost every time at Balls I've seen one tried, there have been issues. Presumably for 1500 bucks there are none with this one.

Not being a radio engineer, I don't have the kind of in depth knowledge required to properly critique the unit, but the technology does seem a bit long in tooth. For this kind of money, i would hope to see a DSS unit that is completely encrypted, like the state of the art staging and deployment devices offered by say Jim Amos at Missile Works.

Along with john coxx, i'm also a little leery of relying on a reed swich to prevent unplanned ignition. While the open circuit resistance of these are very high IIRC, they can be jostled and if a gust of wind were to take down the rocket, might it be possible to have a very large and fire breathing land shark on the loose? I don't know but I think its a fair question. I would rather see encrypted receivers both inside the rocket and at the battery site. But again details are a bit sparse. Maybe the manufacturer can comment.

where can I buy these?

What are "these"?

Do you mean this: http://www.spacewarptechno...WT/SWTD1P4L/SWTD!P4L.htm

If so follow the link in the page to email them for more info.

The web page was not updated as quickly as I had hoped. It has now been updated. Hopefully, the update answers most questions. I have responded to some questions below:




1) The Magnetic interlock key is on the receiver. I readily agree that the receiver should have a safety shut off while any one is at the pad. However there should be an Interlock at the transmitting site as well.

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The system comes with two interlocks: one on the transmitter and one on the receiver side.
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2) The pad cables are 12' long. This is a remote system capable of launching High powered rockets (why else would I be interested in the posting on Rocketry Planet). This means that "as is" when a user arms the receiver with the Magnetic interlock, he is then 12' from what ever size HPR motor. (seems kind of wrong for a system that is $1499)


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Actually no, system initialization requires all cables to be powered up and the piezo buzzer of each line activated to confirm each line and buzzer is working. After initialization of the entire system, the transmitter interlock is disconnected and the transmitter once more tested to verify the lines can not be activated. Again, all lines must have been verified to work and then silenced. The transmitter interlock has to be activated and verified to be dead. The timer power disconnect is to be activated before attaching the cables to anything. Once the timer has been set for 1 to 15 minutes, the user has that much time to attach the cables. The timer can be reset as often as necessary until done. Optionally, one can use the receiver's magnetic interlock to power off the receiver and then use the timer before powering the unit back up to ensure no accidental firing while near the launch site. Since standard extension cords are used, one can attach a longer extension cord to increase length. .
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3) Why do many of the vendors in the hobby lead marketing statements "No Amateur Radio License Required". Ok if a Ham license is not required, then what is the FCC compliance of this system?

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The transmitter and receiver are produced by another company. The unit is FCC compliant. The unit has a 10 mile plus advertised range with appropriate antennas which SWT does not sell or recommend. .
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However this is a very expensive offering, the product quality and information should match the price. But you know, according to the manufacture this device is "Designed for the Serious Rocket Scientists" and "$h!t Happens"


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A very nice and inexpensive system anyone can build is referenced on the web page. Yes $hit does happen which is why the unit has three safety systems to prevent accidental launching. In short, an accidental launch is not likely. What is more likely is a ladder falling on a launch control of a non-remote control launch system causing a premature launch of a very big rocket. I believed this type of situation happened last year. .
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