SARCTRAC Mk2

Hi Jeff,
Yes, the SARCTRAC Mk3 Sensor and WiFi dongles can be retrofitted to SARCTRAC Mk2, or to our free, DIY, Mini Satellite Antenna Rotator. They will be available separately, as a kit, when we have finished our current production effort and have them in stock.
73, Julie and Joe

Hi Shaun,
Unfortunately the IC-705 requires HAMLIB 4.0 or greater and, although we tried, there would be significant modification to SARCTRAC Mk2 to support it. This is why we moved away from incorporating radio support in the rotator itself. There was also a large demand for SARCTRAC Mk3 to use an external tracker and radio controller like HRD. So we went that way. It would be possible to retrofit SARCTRAC Mk3 dongles to the SARCTRAC Mk2 rotator. More on that after our current production effort, when we have SARCTRAC Mk3 in stock.

I've been a proud owner of a SARCTRAC Mk2 for quite some time! I love it!

One of my good friends bought the Mk3. He mentioned that you might be working on a kit to convert the Mk2 to an Mk3. Is that true? If so, could you provide some details on what the kit will consist of, when it would be available, and how much it would cost?

Thanks so much!

is there a video how to update software for mk2 so i can use an ic 705 would help me a lot thanks shaun2

Hi Daryl,
According to AMSAT UK RS-44 uses the following frequencies
Beacon: 435.605 MHz – transmits CW call sign RS44
Inverting transponder:
Earth-to-Space: 145.965 MHz +/- 30 kHz
Space-to-Earth: 435.640 MHz +/- 30 kHz
The correct entry for the SARCTRAC Frequency / Mode Database would be:
[' RS-44 & BREEZE-KM R/B ',['NORMAL','BEACON'],['SSB INVERTING TRANSPONDER','CW BEACON'],[[435.640,'LSB',145.965,'USB'],[0,'LSB',435.605,'CW']]],
This line needs to be inserted, in alphabetical order, into the freq-mode.txt file, in accordance with the SARCTRAC Mk2 User Manual.
73, Julie and Joe.

Daryl responded:
Hi Joe & Julie,
THANKS for the prompt response and the text line for RS-44.
I am happy to report that I have inserted the text in the freqmode.txt file and it works fine.
Cheers, Daryl.

Hi, I would like to have satellite RS-44 appear in my list of available satellites. I see it is in my amateur.txt TLE file but not in the freqmode.txt file.
I understand I have to enter details of the satellite in the freqmode.txt file but cant get my head around the format I need to enter.
Help required.
THANKS Daryl de VK3AWA

Hi Albert,
We use the ArrowII Antenna. See here: http://www.arrowantennas.com/arrowii/146-437.html
However, there are some others that would also appear to be suitable.
Search online for "dual band satellite antennas".
Kind regards,
Julie and Joe.

Hi guys, First of all I would like to say thanks for your dedication and your passion to investigate and improve day by day…
I have a question… Which antennas do you suggest for your rotator? Just to don’t overload the system
(Brand and model, please)
I will used it with my Ic-910H
Thanks and greetings
Albert

Hi Brian,
The lift-arm construction is described on page 30 of the manual as:
1. Round the sharp edges of a lift-arm made from 500x30x30x3mm aluminium angle.
2. Make a counterweight from a 101x51x25mm diecast aluminium box: Filled with lead to 860g (for the Arrow Antenna).
3. Attach the counterweight to one end of the lift-arm with self-tapping metal screws.
4. Attach the antenna to the lift-arm using Velcro. This is for quick release of the antenna and hand-held operation, if required.
5. Attach a 6mm shaft-hub to the lift-arm close to the balance point using 3mm bolts, flat washers and nuts. Ours was positioned 140mm from the antenna
There are many other approaches, as shown here: https://www.sarcnet.org/rotator-mk1.html#StatusReported
It helps if the whole assembly is a little front-heavy, at the shaft hub, to reduce motor/gearbox backlash.
Kind Regards,
Julie and Joe,

Hello -

I received my SARCTRAC Mk2 a few months ago and am just beginning to assemble the station around it. I am curious to know what others have done to fabricate the counterweighted lif arm if they are using an Arrow Satellite Antenna? I have seen manual mounts online using 1/4" aluminum "L" brackets which is what appears to be in use in the SARCTRAC videos (the metric version of that obviously!). What weight has been a good counter balance for the antenna that has worked with the rotator and what material have you all used and been successful with?

Thanks and 73,
Brian

Hi All, received my rotator a week or so ago, Rotator works very well, have been testing and it picks up GPS just fine and can track well. Looking forward to IC9700 support being included in a future update as this will save me taking a computer with gpradict/hamlib to do the doppler tracking!! The limited time I have to use radio means I seem to miss all the good passes, so yet to make a contact, but will soon no doubt

thanks for great bit of kit

Cheers

Cliff ZL1CTS

Hi Rick,
We have completed our production run of 50 SARCTRAC Mk2 units for 2021. They sold out in less than two months! Selling rotators, of course, is not our core mission. We don't think we will do any more this year, but we will let everyone know if we do. HAMLIB 3.3 has been upgraded to HAMLIB 4.1, which may support the radios you have. We expect to be working on a software upgrade for that, before the next production.
73, Julie and Joe.

I am interested in your rotor system, but the website says out of stock. I am volunteering with the local CAP squadron as a STEM / communications senior. Your system looks like a perfect way to demonstrate Amateur Satellite operations. Let me know when you have more units manufactured. I will use either the FT736R or the IC9700.

73 Rick Bunn / N4ASX

Hi Steven,
SARCTRAC has two USB ports. The FT-817 would be connected to one port and configured as a receiver, while the FT-818 would be connected to the other port and configured as a transmitter. You need a CT-62 CAT cable for each. Yes, we have plenty of parts. You need a home WiFi router / access point, or a mobile device personal hotspot, with Internet access. SARCTRAC only needs the Internet to download new orbital element libraries, occasionally, but it is controlled from any web browser over the WiFi network. It was designed for portable operation.
73, Julie and Joe

I just found this product while scanning the web. This looks great. A couple of questions. I have a Yeasu FT 817 and A Yaesu FT 818 I want to use one for xmit and 1 for Rx connecting via the the Ct62 cables. Where do they connect to the controller? do you offer repair parts should I somehow break something? Do I need to have internet/ Cell connection to make this work? thanks for the help.
Steven

Hi Frank,
Bluetooth is not a CAT option in this case. We tried running several types of serial Bluetooth adapters with the built-in RPi Bluetooth driver and none worked. Also, SARCTRAC was designed for portable, attended operation, not permanent installation with remoted or unattended operation. Operating SARCTRAC in this way would be unsafe and may cause damage or injury.
73, Julie and Joe

Hi Julie and Joe,
I'm still reading all the information you send to prepair myself for the installation of the Sarctrak mk2.
I was wondering if its possible to use bluetooth for the CAT connection.
I have this working with the hamradio software on a raspberry, and this works great.
73, Frank PA3EMT

Hi Pablo,
Thanks for the kind words. It is nice to get feedback. The FT-817 has two VFOs, for TX and RX, and it must be set into split mode. For the FT-817, SARCTRAC must switch TX/RX VFOs on a programmed basis, say 1 TX to 4 RX. Unfortunately the FT-817 exhibits all the radio control anomalies identified here: https://www.sarcnet.org/sarctrac.html#RadioControl. That means that when it switches to the TX VFO to program it the uplink frequency is heard, momentarily. This is probably what you are describing. Some radios can do the TX VFO programming in the background. This is all determined by HAMLIB. For digital modes you need to interface audio tones and PTT to the rig, not the rotator. For the FT-817 there are choices to be made using either the ACC or DATA connectors for this. Bear in mind the 1Hz Doppler correction rate together with the above radio control anomalies would not support digital modes e.g. APRS/FT8 via an SSB transceiver, if that is what you were thinking.
Hope that helps
73, Julie and Joe.

Hi Julie and Joe, well I got the mount, followed the instructions and..PRESTO!! AMAZING! Today was the second day I was playing with it, receiving satellites I never even knew existed. So far no FM birds flying over me but with my FT-817 I'm sure the QSOs are coming. Two question a few times when receiving the asterisk birds the receive/transmit will cycle back and forth, is that normal? Also I'd like to work the digital birds, so if I connect the CAT cable to the computer instead of the mount, is there a way to setup this system for digital transmission on the ssb digital birds?. Thanks again! QRV de Pablo Lewin WA6RSV (YouTube video coming soon).

Hi Daryl,

Well done on your first satellite QSO! Working FM satellites is easy, especially if you have programmed in 3 Doppler Frequencies (+5kHz, 0kHz and -5kHz) into your VHF/UHF handheld and change channels at the start, middle and end of a pass. Using two handhelds, one for the up-link and one for the down-link is better, as you can hear your own signal from the satellite. If you rig up a PTT headset, you can simplify the audio interface. Pointing a Yagi antenna is not too difficult, either, if you study the satellite pass and have a good sense of direction. And, once you have received a signal, it is easy to peak up the Yagi direction. SSB satellites are a little more difficult, as you have to constantly adjust the frequency, but they are a very rewarding source of contacts. It is good to get some experience, manually tracking satellites, because you learn a lot about the process.

The main reason we developed SARCTRAC was that it was hard for little kids to hold the antenna and point it in the right direction for any length of time. Our original Arduino tracker was an improvement, but it took so much stuff and so long to set it up we often missed a pass. SARCTRAC just works and lets us concentrate on making contacts. We like working from parks and summits. A satellite contact, while portable, is a real buzz. It is now as easy as setting up our tripod, attaching the antenna, connecting SARCTRAC and an FT-817 to a battery and waiting for a pass.

73, Julie and Joe.

G’day, I’m itching to get my hands on MK2. I have had my first taste of FM satellite ops over the Christmas break and quickly discovered operating a beam hand held is not for me.
Cheers All de VK3AWA

Hi Shaun,
You expertly demonstrated that it was easy to restore a SARCTRAC backup to fix a corrupted file. Well done!
SARCTRAC uses the latest version of the Hamlib Radio Control Library.
At the moment Hamlib does not support the Icom IC-7900, nor the Icom IC-705, which are relatively new models.
We expect they will be supported in Hamlib version 4.0, but we are not sure when it will be released.
The good news is that SARCTRAC is fully field-upgradable including its libraries and even the operating system.
So it should be no problem to install when Hamlib version 4.0 is released and we have tested it.
Happy tracking and keep in touch.
Kind regards and stay safe,
Julie and Joe

this works out of the box well worth getting i was messing about with it i corrupted file my fault I Am sure but support was spot on it would be nice to have ic 7900 ans ic 705 supported thanks joe