Orion RIT-XIT Intermittent Encoder Fix

(scroll down to Aug 9, 2010 and later for the actual fix that works - earlier info included for historical perspective but the earlier suggested fixes do NOT hold up)

From the Ten-Tec Reflector January 20, 2005

I know this sounds stupid but this corrected the RIT encoder problem for my Orion and another ham friends Orion. Take hold of the encoder knob and pull hard on it like you are trying to pull the knob off, then let go. Once I did that my encoder started working again and has worked and is still working today. This also worked for N4ZZ's Orion. Strange but a simple fix for us, so I hope it works for you. It might save you a trip to Ten-Tec.



April 8, 2007

There must be a plate through involved with the RIT control. Mine started acting up shortly after I bought my Orion in 2003. I eventually removed the top and bottom covers and removed the 10 screws that held on the front panel. I used my pencil soldering iron and re-heated the pins for the RIT control. It worked fine until earlier this week when I pushed the knob to reset it back to ZERO. Then it started acting up again. Yesterday, I went through the same process again and now the control is working fine. Be careful when re-heating the pins. 3 of them are close together.

You can do the repair by just laying the front panel on the knobs and do not have to unplug anything. Good luck.

John W3GQJ

July 14, 2008

I took my Orion apart again today. My first experience with the problem was in September, 2004. Many times I had soldered the encoder pins thinking it fixed the problem. A year later it would come back and be temperature sensitive. Solder pins again and problem would quit. About three months ago I had the problem again and soldered pins. A week later it was back. So in frustration, I decided to master this challenge.

I removed the logic and display board today. Before I removed it, I gently pulled on the logic board and could make the problem appear. I then pushed on the board and the problem disappeared.

After I removed the board and carefully looked at the pins, pins 3 and 4 of J8 did not have any scratch insertion marks on them. I looked closer under a magnifying glass on noticed that pins 3 and 4 were slightly out of alignment. They were bent about 1/32 toward the display screen. I took a picture with digital camera and the misalignment is visible. (I am sending a copy to Ten-Tec for their files.) Using my finger nail, I bent pins 3 and 4 away from the display until they lined up with the other pins. I then remounted the logic board / display board and then tried flexing the logic board again. This time I had no problem. Evidently the female connector sockets only have contacts on one side because of small size.

If the RIT/XIT quits before I "check out," I will let the list know. But I plan to try to reach the nineties which means I will probably have a different rig by then! =)

Thank you everyone who sent me their observation and John, K1ESE, who worked on his rig this weekend and confirmed that the problem was in the area of the "B" ribbon cable.


John W3GQJ

July 30, 2008

At Paul Clinton's urging, I performed your repair today, John, and my RIT and XIT are now working for the first time in about 3/4 years. This could be an oxidation problem that simply unplugging and plugging the connectors wipes off, but, I suspect that you are right and that a couple of the pins were not mating correctly. Nice catch after all the discussion of this problem!

Stan, W4AG

February 7, 2009

After all my work, the intermittent RIT/XIT problem is back! :={ This time I am going to use the standoffs that Ten-Tec sent me so I can mount the front panel away from the case. Then when the control does not work, I can use a plastic stick and touch suspect parts and see if it starts working again. It is not going to be easy because I can make it work again just by pressing on the front panel. That is why some people had said pulling knobs cured the problem. More to come. And I thought for sure I had it when I found the pins with no evidence of rubbing the socket.

John W3GQJ

February 18, 2009

Does anyone have an Orion I with an intermittent RIT/XIT control? Mine has become intermittent again and I am trying a new idea. If yours is intermittent, I suspect the connector J8. I have had my entire front panel apart and examined the PC board and ALL connections look good. I found that if I apply pressure to the front of the case between the sweep button and the LCD display, the problem will cure itself. Connector J8 is located behind this point. Originally I noticed that pins 3 and 4 of J8 did not have any scratch marks from being plugged into connector J15. I also noticed that my pins 3 and 4 were bent out of alignment. I straightened them to align with the other pins. This time I bent the pins a little further hoping to get more friction with the connector. So now it is a waiting game to see if it fails again.

If your rig is intermittent, please try applying pressure to the case between the sweep button and the display. If it cures the problem, this helps to confirm that a marginal batch of connectors could be the source of the problem. I have no intention of replacing mine. At 70, my eyes, fingers and dexterity ain't what it was as a kid! I will just apply pressure a few times until I have a good connection again.

John W3GQJ

From the Orion reflector July 27 - August 9, 2010

A few months ago I had a problem with a bad mechanical encoder in my 565 (Bandwidth, had a dead spot). I decided that as long as I had to replace one of them, I would replace them all.

After replacing them, I tested them all to be sure they worked correctly.

Then a couple of weeks ago, I had reason to use the RIT control, and noticed the problem you (and others) have mentioned. I knew it wasn't a bad encoder (Or shouldn't be, since they were all replaced), so I opened the case, removed what I needed to, to get to the boards behind the front panel (if you check Ten-Tec's site and take a look at the V2 Logic Mod you can see how to do it). I pressed down on the encoder board near the header where it plugs onto the switch board socket. This fixed the problem.

Just thinking out loud, I wonder if it might be a matter of the strength of the contacts in the socket and a little aging of the contact surfaces in the socket and the mating pins. If it happens again on mine, I am thinking about using a very thin film of silver contact grease (CircuitWorks CW7100) to see if it permanently corrects the problem. It would have to be carefully applied to the header pins (Q-tip) and you'd have to be sure not to get it on anything else or across the socket surface, but I think it's worth a try.

Something I did notice when reassembling the Orion after I replaced all the encoders, is that there is a very slight bow along the control board when the encoder in pressed into it's socket (I assume from the pressure of 24 pins being mechanically 'captive' to 24 socket connections). This might have caused a 'meeting' problem since the section of the header that the RIT encoder goes to is near the center of the string. There are 4, 6 pin sockets mounted end to end, not 1, 24 pin socket. Over time, with a slight alignment difference, the connection could get noisy.

But, the more I look at the schematic, the more I wonder if the problem is actually at J15, after the 100k resistors. This is one of the sockets the logic board plugs into, with very long pins. I note that the picture of that board in the V2 mod doc shows non-gold plated pins. I don't remember if they are on mine or not. This would seem to be the most likely 'bad connection' point. It is also where the lowest current pulses would be.

This would explain why pressing on the face of the Orion near the Main AF control temporarily fixes the issue as well.

I am a bit surprised these pin are not gold plated, if the production Orion is the same way.

I found that the pins from the logic board to the front panel sockets are indeed tin plated. Luckily the sockets are too (or not so luckily) but in that environment and with no wiping current, tin is not such a good thing.

I applied the grease (a little tedious but not too bad). [N1EU note: see rit_cond_grease_fix.doc ]

The grease seems to be about the same consistency as white clay with plenty of moisture (thicker than I imagined), but this is a good thing: it will stay put, just a little more difficult to work with.

update: RIT is still working. It had been very unstable until this was done. I have had the Orion on for many hours and off for many hours, testing every time it crossed my mind (which has been often). I even turn it on for long enough to test when I walk by it, if its off.

I really suspect fretting of the tin contacts as the cause of most of the RIT issues. Doing anything that moved the connection a little (or alot) would temporarily fix it, but didn't address the real cause. It just so happens the RIT connection was mostly affected (maybe some combination of the location of the pins, the sockets, the mounting of the 'layers' of boards, etc). The way encoders are read by the processor, only one pin need have a problem and it could stop working (depending on how the programmer decided to handle errors).

Anthony, K4ZNO

October 2011 - From Ten-Tec Engineering

The problem comes from having the gold posts on the one board, and then non-gold on the female connector. About 20 pins or so. Over time, as we all know, oxidation occurs because they aren't the same material. Now, in the 566, it isn't a problem, because the female connector used has two "grabbers", so, they normally always have one of the two grabbers locked onto the posts hard. In the 565, there is only one grabber, so, that is why some people get it to work again with the "jerk the RIT knob" trick. It may or may not remove enough oxidation, a few jerks may work, but one too hard can cause other damage.

Step 1 is to try the "jerk the RIT knob" trick. We don't promote it, but in some cases it has been known to work.

Step 2 is to remove the front panel, remove the RIT from the front panel, clean the male connector and female connector very carefully with deoxit (light-red), and if you then have any, a light spray coat with PreservIt (light blue). This second step isn't required, but it would prolong the time between ripping it all apart. Takes about 1.5 hours or so to do it, when you know what you are doing.

Step 3 is to remove the female strip connector, and replace it with the same we use in the 566. Granted, the same problem can occur, but we have not had any complaints from anyone that we have done step 3 to, or that have an Orion 566. I don't advocate customers doing this, since it is a long strip of solder to remove, and can damage the board in other ways. If you have a professional technician friend, this approach is up to you.

January 2014 - N1EU

I had the Ten-Tec "step 3" repair above performed on my Orion but it failed again after several months. I decided to try K4ZNO's above fix. I applied the silver conductive grease to the encoder stake pin connector as well as the two vfo encoder connector pairs. You need to remove the front panel and the logic board per the V2 mod instructions. Remove the knobs on the 6 small encoders (see separate knob removal instructions). Remove the screws securing the grounding wire/lugs to the vfo encoders and remove the cables/connectors from the vfo encoders. You then need to remove the 36 screws securing the front panel pcb in order to lift it up to gain access to remove the threaded nylon bushings securing the 6 encoders to the front panel pcb - use 1/2 in nut driver. You can then lift up the encoder board. I applied the grease with a tooth pick, carefully dabbing each pin. Be very stingy with the grease because it will really spread and ooze out after you remake the connections and WILL cause short circuits in the future. In fact, you should make/break the connection several times and then carefully clean off the oozed out grease. When you reassemble everything, be very careful to not over-tighten the threaded nylon bushings on the 6 encoders or the push switch action will be impaired and control rotation will not be smooth. I would say the job start to finish can be performed in about an hour and there's nothing particularly difficult about it. I will report back in several months if the fix held. (April 2015 - fix has held)

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