Hi! I have the AlfaSpid elevation rotator with its original controlbox. Trying to use it for my 3.1m dish projekt. But unfortunately when checking the performance with a 10bit graycode encoder the controlbox lose its calibration quite often so it will not be good enough for EME. Have also big problems in my troposystem with a Prosistel D controlbox connected to a Prosistel rotator, it develops a 7degree error from cold start. (Driffting slowly for 3 hours) Seem like many of the available amateurradio rotator control boxes only works for shortwave or small vhf antennas. Will use VK5DJ control pic for my dish projekt. 73 SM7GEP Hakan

Hi Serge , I am using it too on 2m. Same pb ( more than 5 deg offset in fact) and it is not the antenna slipping on the mast. I received many direct mails since this morning and I can tell U many people agree. 73 Dom Le 30/11/2015 16:02, serge a écrit :

Hi, In fact, the software does not count the pulses but transitions, positive or negative, so 720 transitions / 360 °. Indeed, the reed sensor may stop in the middle of a pulse cycle. With a good algorithm, we can keep the half degree for a cycle pulse ratio of 1/2. But this remains a relatively low and hazardous system on a so good, simple and ingenious, mechanic. 73, Lucien F1TE From: F1TE Sent: Monday, November 30, 2015 5:35 PM To: serge ; jrgroeger(a)ewetel.net ; moon-net(a)mailman.pe1itr.com Subject: Re: [Moon-Net] AlfaSpid rotator problem. Hi, This problem is congenital on this model of SPID rotor. It is due to bad algorithmic processing of pulses. Indeed, it would continue to count up, or count down depending on the direction of rotation, at least 500 ms after the electrical stop of the rotation command, to not lose an "extra-pulse" caused by the inertia of the rotor motor. The inertia of this one ! http://www.bobinage-induit-bemts-16.com/angouleme/wp-content/uploads/induit… This is the main cause of shift A loss of a pulse causes a shift of one degree. But even by make, like me, another controller with another firmware, shift is always possible, pulse counting system can not be accurate and the subject “SPID rotor” comes up regularly like bad weather. With better algorithmic processing pulses on my home made controlbox, I no longer resynchronization every two to three months. Sufficiency in 144 MHz The only one definitive solution I found is to mount a MAB25 encoder inside. http://www.f1te.org/index.php/realisation/rotors/modification-spid-rotor 73, Lucien F1TE From: serge Sent: Monday, November 30, 2015 4:02 PM To: jrgroeger(a)ewetel.net ; moon-net(a)mailman.pe1itr.com Subject: Re: [Moon-Net] AlfaSpid rotator problem. Hi Jo & Dominique I have an Alfaspid motor & have the same problems. I did get a new control box from the folks in Alberta & that did not cure the problem but improved the calibration greatly & I can live with that on 144Mhz. So once in while i have to recalibrate the system. The issue is the process is cumulative so if you are 1 or 2 degrees off i can live with that on 2 M but then the error increases as the time goes by & then you end up being 5 degrees off. Not good. Serge ve1kg ----- Original Message ----- From: <jrgroeger(a)ewetel.net> To: <moon-net(a)mailman.pe1itr.com> Sent: Monday, November 30, 2015 12:28 PM Subject: Re: [Moon-Net] AlfaSpid rotator problem. _______________________________________________ Moon-Net posting and subscription instructions are at http://www.nlsa.com/nets/moon-net-help.html -------------------------------------------------------------------------------- _______________________________________________ Moon-Net posting and subscription instructions are at http://www.nlsa.com/nets/moon-net-help.html