View Full Version : Ham M Rotor

03-09-2003, 06:57 PM
I just got a Ham M rotor with a tower I bought. It's old complete is the old brown bakelite case but does not appear to be in to bad of condition. The series of 4 538 appears on the rotor and the control box and I am assuming that this is the Ham M?
I heard that the rebuilding information and a parts list is available on a CD ROM?
Is there anyone that knows the source for rebuilding information?


03-09-2003, 11:03 PM
Try www.rotordoc.com/parts.

I got the complete manual downloaded on internet. #I believe I went to www.mfjenterprises.com and found it. #

It does not give step by step procedure but it had all part numbers and showed how they were arranged

Good Luck. # # #BTW the 3/8 inch balls are available at any bearing supply.Get stainless steel.

03-10-2003, 12:20 AM
If you have problems downloading the manual from mfj, the manuals on all of the older CDE rotators are on BAMA (Boat Anchor Manual Archives) at http://bama.sbc.edu/cde.htm free for the taking.

I rebuilt my Ham II, which is the same rotor but different style control box, three times before it finally really went "south" after about 28 years of use. The main thing that goes wrong in the rotor itself is the ring gear. Since this is also a primary source of braking, they often crack. I know that replacement parts are available from several sources including Norm's, Texas Towers, and possibly from mfj. The ring gear was the problem in every case. The same ring gear is used in several CDE rotors from the old AR-22 (which has no brake and only 6 ball bearings) through the CDE-44, through the Ham series (Ham-M, Ham II, Ham III, and Ham IV).

The other primary source of problems is the starting capacitor in the control box. Over the years I went through at least 4 of these. If the rotor is slow to operate, or if it stops operating completely, replacing the starting capacitor fixes the problem at least 9 times out of 10. Replacement capacitors are available from the same sources as the mechanical parts and can often be found locally at a shop that repairs motors since starting capacitors going bad are a very common occurance. Slowing down of the rotor in cold temperatures is a sure sign that your capacitor is starting to go bad.

If you take apart the rotor, make sure that you don't lose the ball bearings! They are held in place by a nylon retainer. Put the rotor on a tarp, etc., so that the bearings don't roll very far when you take the rotor apart. If they show signs of wear, then replace them. However, they are pretty rugged and I never had to replace any of those in my Ham II. Clean the assembly completely and then use a good quality grease (automotive wheel bearing grease is inexpensive and works fine) on the gears run by the motor.

I use a thrust bearing on top of my tower to support the weight of my antennas and the sideways force is taken up by a plate with a hole in it. Thus, all the rotor has to do is to actually rotate the antennas and to hold them in place after rotation. I can actually take my rotor loose and turn the entire array with one hand. You can see a photo of this at http://home.attbi.com/~k9sth The rotor lasted for about 28 years before several hours of wind "gusts" up to over 70 mph finally "did it in". My insurance company paid for the new rotor and damage to the yagis (I have a "rider" that covers any damage at all to my antennas).

Thus, in my opinion, the Ham series rotors are well worth what they cost. 28 years is not the record for a rotor, but the performance over that 28 years was excellent.

Glen, K9STH

03-10-2003, 01:44 AM
TNX for information guys.
Lots of parts out there for the Ham M. And I also found that little brake delay. I think I just might add that when I go through this unit too. Might just make it last longer without the strain the gears coming to a sudden stop each time.
Might even outlast Glens 28 years?? HI HI By teh way Glen, for some reason I cannot get the Boat Anchor Manual Archieves site to come up.

73 Ken

03-10-2003, 04:09 AM
Can you get to the home page, bama.sbc.edu?

If so, then read the comments about problems with various browsers and take the steps that Ken, K4XL, says to take. That should eliminate the problem. For some reason, the software that sbc.edu uses is at odds with a lot of the settings of various browsers, especially Microsoft Internet Explorer. Ken has no control over the basic site so he can't change the settings on it. The changes that you make to your browser have no effect on normal operation.

Glen, K9STH

03-10-2003, 07:38 AM
These CDR rotors can last a long time. I've had a CDR TR-4 rotating antennas since 1959 (44 years). Had originally a 6M beam on it for years; mast supporting it buckled during a wind storm in 77; rotor hung upside down for 2 days and filled with water (I was away). Drained it, baked it in an oven for several hours to dry it out; regreased it using wheel bearing grease, and it's been back on the roof supporting a 6 element FM antenna and 2 TV antennas. I think I replaced the motor start capacitor once.

That's getting your monies worth.
Pete, WA2CWA

03-10-2003, 12:57 PM
Looks like your getting ready to move out to that Rim Country Ken.... Good for you and the XYL... Enjoy it.

As for the rotor, be careful to get the little wafer switches all lined up in order when you put it back together. They can be real tough.

After you get it all put back together, before going to the tower, hook up the control head and make sure is operates correctly and the heading is in the right direction. And that it will make a complete rotation. If you don't get the top back on "just right" everything will look OK but it won't make a complete rotation.

It may not make any difference to you fellas/gals who are in Arizona or California etc but for those in COLD COUNTRY, take some advise and DO NOT use wheel bearing grease in your rotors. When it gets cold, they won't move.

Use some of the synthetic type lubrications and then just a very light coating on the races is all you will need. THINNER IS BETTER !

Good Luck

03-10-2003, 02:29 PM
The rotor on the Ham-M series doesn't have any wafer switches in it! The only switch is the limit switch which stops the rotor from turning more than about 370 degrees. The indicator is controlled by a variable resistor located in the top of the rotor.

Glen, K9STH

03-10-2003, 02:45 PM
OK Glen, I got into the BAMA site and it was the browser settings that was the problem. It did not like the FTP files I guess.
I got the manual for the Ham M and printed it. Only 12 pages.


03-11-2003, 04:20 AM

I guess that was the one - before your time --- huh??

Sorry about that ...


03-11-2003, 05:20 AM
CDE did make several TV type rotors that had a switching assemby inside that worked lights in the control box. I can't remember if there were just 8 or if there was a model with 16 lights. All of the Ham series rotors used a meter readout that was controlled by a wire-wound potentiometer located in the top of the rotor itself.

I am not sure about Alliance, the only versions that I have seen from them used either the single switch to send pulses like the CDE AR-22 or a potentiometer to run a meter.

Glen, K9STH

03-11-2003, 01:13 PM
Correctly identifying your model of CDE/HyGain rotor
A guide from Norm's Rotor Service to help you identify your rotor.

Rotor controllers are generic; they may be common to multiple types of rotors. For example the HAM- M and TR-44 rotors use the same controller. The CD-44, HAM-2, and HAM-3 rotors share the same controller. The CD-45 and the HAM-4 (HAM-IV) share the same controller.

All rotors made by Cornell-Dubilier (CD) and by Hy-Gain have the model number stamped into the casting. The bottom of the actual rotor (not the lower mast adaptor, but the actual rotor itself) must be removed to see this identifying model stamp. On the bottom plate of the rotor itself, somewhere near the terminal strip, you will find the model number and the date of manufacture.

All of the bell type rotors are the same, with the exception of the HAM series, which has the brake housing attached and add an additional 3" to the overall length of the rotor.

Here are some examples of what you will find:
On a TR-44/CD-44 it will have stamped "TR-44 SER 3 235" or "CD-44 SER 3 647." In the case of the TR-44 it is a series 3 and it was made in 1972, the 35th week of that year. In the case of the CD-44, it is also a series 3; it was made in 1976, the 47th week of that year. The TR-44 rotor and the CD-44 rotor are identical; the only difference in the two was a control box design change.

In the case of the HAM-M and the HAM-2, the rotors are identical, and the only difference was a control box design change. A HAM-M or HAM-2 would be marked "5 523," which would indicate a series 5 rotor, made in 1975, the 23rd week of that year. There was also a series 4 HAM-M rotor, and many people identify this as a HAM-4, which it is not. A HAM-M series 4 might be marked as "4 532," indicating a series 4 HAM-M rotor, made in 1965, the 32nd week of that year.

The HAM-3 rotor is stamped as HAM-3 with the month and year of manufacture. There were two series of HAM-3 rotors. A rotor marked "HAM-3 SER 2 MAY 76" would be a HAM-3 series 2 rotor, manufactured in May, 1976.

The HAM-4 rotor (which is exactly the same thing as a HAM-IV rotor) would be marked similarly. It could be marked with either the Arabic numeral "4" or the Roman numeral "IV" but there is no difference. There was only one series of HAM-4 rotor.

The T2X or TailTwister rotor is marked in the same way as the HAM-4.

The new HyGain rotors manufactured after 1/1/2000 will be stamped with an MS instead of an S1. For example: T2X MS APR 00.

The Alliance HD-73 rotor came in two models. The rotor in both models is the same. The difference is that the earlier model, designated HD-73, had a control unit with a silver, round-style power on-off switch; the later model, designated HD-73-1 had a control unit with a black rocker- style power on-off switch.

What is the difference in the Ham series of rotors?
The Ham-M rotor was released in 1957 and there were 5 series with the last rotor being produced in 1973. The Ham-M rotor would have the series number, 1 - 5, followed by 3 digits which indicated the week and year of manufacture. For example, a rotor with the series number 5 322 would be a Ham-M, series 5, manufactured in the twenty-second week (the '22' in '322') of the year 1973 (the '3' in '322')

A Ham-M has a single-levered control box with a meter. In 1973 the mold for making the Ham-M control unit shell was destroyed in a fire. So rather than spend the money to replace the mold, the Ham-2 was born. The rotor was the same as the Ham-M, but the control unit was replaced with a three-button unit with a continuous meter reading.

In 1977 the Ham-3 rotor was released. The Ham-3 supported a new motor with an internal brake, as well as a brass motor gear. The brake wedge was redesigned, as was the brake housing, which gave the new unit a capacity for more wind surface area. The control unit for the Ham-3 supported a new PC-board-mounted meter.

In 1978 the Ham-4 or Ham-IV rotor was released. This rotor had a new steel ring gear and a reinforced upper mast support. The only changes to the control box were the addition of a new face plate, plastic top and bottom covers, and a new meter with reversible meter scales. Also in 1978 the TailTwister rotor, commonly refered to as the "T2X," was introduced. The T2X is a Ham-4 with an even heavier upper mast support, a heavier brake wedge and brake housing, and 40 additional ball bearings. And the TailTwister control unit has three LED's that the Ham-4 doesn't have.


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