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Restored morrow mobile twins

Discussion in '"Boat Anchor" & Classic Equipment' started by W4OP, Apr 16, 2012.

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  1. W4OP

    W4OP Ham Member QRZ Page

    Ii have just posted the restoration of my Morrow mobile Twins- MB-6 / MB-565 on my restoration site at:
    last thumnail- lower right.

    As can be seen in one of the photos- these were in very tough shape mechanically and had a number of intriguing electrical issues to be solved. I believe these to be the Cadillac of the mobile Twins both from a design and feature standpoint.

    Dale W4OP

    Sorry, if this post is a repeat. I tried to post earlier and it looks like it didn't 'take'.
  2. K9STH

    K9STH Ham Member QRZ Page

    There are those who think that the Gonset G-66B and G-77 are better! :p

    However, the restoration looks excellent.

    Glen, K9STH
  3. WA7PRC

    WA7PRC Ham Member QRZ Page

    Very nice work, Dale! However, I think Pat/WA6MHZ will be more interested in your:
  4. W4OP

    W4OP Ham Member QRZ Page

    I restored the Gonset Twins for a friend many years ago Glen, and I am sure I have forgotten some details.
    I would still pick the Morrow RX because:

    1. Squelch (which could be very useful for mobile work)
    2. Crystal calibrator with a separate dial calibration knob.
    3. The field strength position which could also be very useful for tuning up a mobile antenna.

    The Morrow TX would also be my pick:
    1. The meter switch allows one to monitor Grid current, RF plate current, modulator plate current and modulator bias
    2. Zero beat switch position- I don't recall the Gonset had this, but I may be mistaken.
    3. The plate modulator is built in- wasn't it separate in the G-77?

    The modulator in the Morrow uses a phase inverter to drive the P-P 6AU5's. I recall the Elmac interstage transformer as being a problem in that TX (AF-67). It need not be but was. I don't recall how Gonset did this.

    I have long been a Gonset fan- particularly their hybrid 6 and 2M rigs- a little ahead of their time, but usable even today once you tame the IF.


    Dale W4OP
  5. AF9J

    AF9J Ham Member QRZ Page

    VERY cool! IIRC, the Morrow Twins are the only ham radio gear that Morrow made. They decided to abandon the ham market, and just concentrate on aircraft radios and avionics.
  6. K9STH

    K9STH Ham Member QRZ Page


    Morrow also built 2 other units for amateur radio use:

    The Model FTR, introduced in 1954, which was a receiver fixed tuned to 1525 kHz for use with the various mobile converters popular at the time (Gonset Super 6, Super 12, RME, etc.). This receiver included a BFO, r.f. stage, bandpass filters, "S" meter, etc.

    The Model 5BRF mobile converter which covered 80, 40, 20, 15, and 11/10-meters. This was designed to be used with the FTR but could be used with basically any AM broadcast receiver.

    Glen, K9STH
  7. W4OP

    W4OP Ham Member QRZ Page

  8. K9STH

    K9STH Ham Member QRZ Page

    I basically considered all 3 of the "twins" series just to be a continuation of the same models. Besides the MB-565 transmitter and the MB-6 receiver, there were the MBR-5 and "Falcon" receivers, and the MB-560 and MB-560A transmitters. The "Falcon" receiver differed from the other receivers in that it had several i.f. bandwidths ranging from 2.8 kHz to 9.2 kHz. Also, the "Falcon" had separate broadcast band capabilities and had the Model BCT Conelrad monitor included. The "Falcon" was also available less the Conelrad monitor, but still with broadcast band tuner, for $19.55 less.

    Glen, K9STH
  9. KM1H

    KM1H Ham Member QRZ Page

    Very nice indeed Dale.

    In the late 50's my mobile installation was a Gonset Tri Band converter and TBS-50D which was pretty low buck since I was still in HS.
    Didnt go mobile again until at National where I had a NCX-3 and later a NCX-5 on loan 1963-69.

    Havent been HF mobile since but if I did it would be those Morrows.

  10. W4OP

    W4OP Ham Member QRZ Page

    Hi Carl,
    I must say, the Morrows do have a nice form factor- I was immediately attracted to them. I have casually looked at my 2nd set of the Twins and see some wires have been unsoldered in the RX, so this is going to be fun.

    I restored an NCX-5 not too long ago. Except for the size, that would have been a wonderful mobile rig and stable as could be for the times.
    Then again, cars back then had room for that rig.

    Dale W4OP
  11. K9STH

    K9STH Ham Member QRZ Page

    In 1965 I ran the Heath MR-1 "Comanche" and the MT-1 "Cheyenne" mobile in a 1961 Ford Falcon. When I pulled them out and went to a 2-meter Motorola T43GGV-1130A trunk mount, my wife was so happy with that "itty bitty" control head that she hasn't complained once in basically 47 years about a mobile in the car! In fact, she insists on having at least a 2-meter mobile, "just in case" something happens, even though we have had a cellular telephone since 1996.

    Glen, K9STH
  12. W4OP

    W4OP Ham Member QRZ Page

    I guess after that pair, anything would be more acceptable. I believe they had the screw holes in the bottom and tops so they could be stacked- at least the HX-20/HR-20 did. That would have made for a formidable occupied volume.

    Dale W4OP
  13. K9STH

    K9STH Ham Member QRZ Page

    The HR-20 and HX-20 used the same cabinets as the MR-1 and MT-1.

    Glen, K9STH
  14. KM1H

    KM1H Ham Member QRZ Page

    The 57 Chevy was easy but a 64 GTO convertible with 4spd followed and that required having it on the passenger seat while commuting and putting in the trunk otherwise. The GF and later wife didnt like it period and I couldnt get her to ride in the back seat on our honeymoon [​IMG]

  15. W9GB

    W9GB Ham Member QRZ Page


    Nice restoration of the Morrow twins. 220 kHz was an odd IF, but I remember that Collins made F250A mechanical filters for some radios that used a 250 kHz IF.
    The found a photo of the original Morrow power supply and speaker on Jim Garland's web page for his Morrow MB-6 receiver.
    Last edited: Apr 21, 2012
  16. W4OP

    W4OP Ham Member QRZ Page

    There were several Morrow supplies- both AC and DC. The one with my Morrows is a real brute (model RTS-600S)- lots of iron.
    Jim's is however, a bit more attractive.

    Dale W4OP
  17. KA4DPO

    KA4DPO Premium Subscriber QRZ Page

    Those are really sweet.
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