ad: vanity

TRA-4 rotor info needed

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KJ4LTC, Nov 27, 2010.

Thread Status:
Not open for further replies.
ad: L-HROutlet
ad: l-rl
ad: L-MFJ
ad: Left-2
ad: Left-3
ad: Subscribe
ad: abrind-2
  1. KJ4LTC

    KJ4LTC Ham Member QRZ Page

    I acquired a rotor, on the bottom outer edge it's marked TRA-4 with a 2 underneath that. Does anyone have any info on this rotor, # contorl wires, which control box, how to check to see if rotor is even good.... any help is appreciated
  2. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Number of wires?

    Doesn't it have two 4-screw terminal strips on the bottom (8 screw terminals, in two rows of four)? If it does, then any of the HAM-M series control boxes will work with it.

    If it's a 4-wire model (one 4-screw terminal strip) then the AR-22 style control box is called for.

    But I "thought" the TRA-4 were all 8-wire. Maybe I'm losing it...;)
  3. W9GB

    W9GB Ham Member QRZ Page

    The CDE/HyGain AR-22, AR-33, AR-40, CD-44, CD-45, TR-4, etc. rotators used the 1950s CDE TRA-4 bell housing which are only for LIGHT DUTY.
    The aluminum casting is not as robust as the one used for the HAM-M (or HAM-II, HAM-III, HAM-IV)
    and of course completely different from that used on the Tail Twister (T2X).

    This rotator series was deisgned for VHF TV antennas .. SO it would be OKAY for VHF and UHF antennas ...
    not suitable for large HF tri-band antennas (inadequate braking and can not handle HF antenna wind loads).

    Does this rotator have the markings AR-40 on the bottom (center) of the rotator?
    This rotator model does have the TRA-4 around the edge/rim of the bottom casting.

    DO you have 5 screw connections on the bottom ?

    RigPix -- CDE AR-40

    The "Bell Rotors" were developed by the engineers at Cornell Dublier Electronics about 1950 starting with the TR-2 and TR-4 series of rotators.
    They were deisgned for directional TV antennas (TV channels 2-6 and 7-13 VHF service) which were just then becoming popular.
    These models were meant to compliment their existing line of smaller rotators and in many cases, turned out to be the `big brothers" as some of the control units would work on both series.

    As Amateur radio antennas also became larger and larger during the 1950's, the need for larger rotators became evident, so sometime about 1956, work started on a heavier design with a separate brake feature to keep the antennas from "windmilling."
    This development eventually ended up as the current HyGain/MFJ HAM IV rotators (larger bell size) that are produced today.

    The Ham-M rotator
    This was the result of beefing up considerably the older style TV rotators with stronger, heavier gears, the wedge brake, and an improved indication system for direct readout to a meter with a scale for NSEWN and degrees from 0 to 360.
    This model, the Ham-M first debuted in November 1957.

    The first Ham-M's, series 1 and 2, used a wiring format that was different and not compatable with later units. While these earlier units can be rewired, it is not generally considered economically feasible or worth the time to convert.

    Ham-M series 3 showed up late in 1959 after numerous complaints about the wiring and the meter "flutter" and the "backwards" scale. SERIES 3 addressed these problems with revised wiring that DOES MATCH the current models, an improved grounding system for the meter feedback circuit, and a more popular scale -SWNES -since most people in the U.S. wanted North in the center of the scale.

    No major changes occurred in 1965 and 1967 when the later Ham-M SERIES 4 and 5 were brought out, but minor improvements continued to be made in reliability. Ham-M's continued until 1974.

    The Ham-II rotators were introduced in the mid-170s (1974?)

    Last edited: Nov 27, 2010
  4. KJ4LTC

    KJ4LTC Ham Member QRZ Page

    just confirmed it is an 8 wire unit, apparently made by "Empire" i think that's what it had before the TRA-4 marking. With all of that said is a HAM series control what i need? Let me check on AR-40 markings....stand by
    Last edited: Nov 27, 2010
  5. KJ4LTC

    KJ4LTC Ham Member QRZ Page

    Ok, removed the bottom mast mount and imprinted under that was TR2 SER 8 T11 awaiting verdict
  6. W9GB

    W9GB Ham Member QRZ Page

    Looks like a VERY OLD .... TR-2 series, which are NOT interchangable with CDE/HyGain HAM series (see below, FAQ #14)
    Norm's Rotor Service OR

    CATS, The Rotor Doctor in Ohio

    They can help you to acquire a proper controller for this old TV rotator (it is not a Ham series).
    They can REBUILD a bad control unit -- the cost is $79, WHEN these units are available. rotor sales.htm

    Identifying Your CDE / HyGain Rotator identify.htm

    Norm's Rotor Service -- FAQ is the

    14. Can I use a Ham-2 rotor control box with my T2X rotor? Are the Ham-2, Ham-3, Ham-4 and T2X control boxes interchangeable?

    Yes, for the most part, all of the 8-wire rotors, EXCEPT for the TR-2 series are interchangeable.
    You can use a TR-44 series 3; Ham-M series 3, 4, or 5; CD-44/Ham-2; CD-44/Ham-3; Ham-4; or T2X control unit with any of the listed rotors or vice versa.
    HOWEVER, the Ham-M and TR-44 series 1 and 2 rotors were wired differently and are not interchangeable with anything else. So, trying to use a series 1 or 2 control on a newer rotor will destroy the rotor pot instantly.

    To be sure that you have one of the interchangeable controls, verify that the motor start capacitor is across terminals 4 and 8. To verify that the rotor is one of the interchangeable models, look for the 500-ohm pot resistance across terminals 3 and 7. If your rotor and control unit pass these inspections, they are interchangeable with others which also pass.
    Last edited: Nov 27, 2010
  7. KJ4LTC

    KJ4LTC Ham Member QRZ Page

    Anyone know where a rotor contol can be found for a TR-2 rotor
  8. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    I don't even remember the TR-2 and I've been using CDE rotators since 1965, some 45 years ago.

    Maybe the TR-2 is older than that, in which case I wouldn't necessarily expect it to work.:p

    Strongly recommend you contact Craig's or Norm's ( and as previously suggested by W9GB) as these guys are the two leading experts in CDE rotators, probably in the world. If they don't have it or don't know what to do, probably nobody does.
    K4FF likes this.
Thread Status:
Not open for further replies.

Share This Page

ad: SDRKits-1