Anyone using the transverter solution from Rene, PE1CMO?

  • Besides my own design transverter (for simplex use) I have a prototype CMO-transverter (because I was involved in the design and wrote the software for the microcontroller).

    It works very well. All LO's (including PLL LNB LO) are locked to GPS (like in my design). Rene's design is based on my philosophy , abeit that his interpretation is

    more professional because his professional business is broadcast (uWave) (video/audio)transmitters. So his component choice is much better than my 'Scooby Doo' built, has lower phase noise(s) and a (much) more efficient 2.4 GHz PA.

    So what do you want to know more / precisely ?

  • Tnx Remco for feedback

    ... I thought of answers like "Yes I'm using it and made my DXCC in 10days" :-) you're right a little bit too unspecific. It's interesting to hear the backkground story of the transverter.

    You wrote "for simplex use" - Rene's design is also a simplex solution - right?

  • Yes ... and no ... if strongly desired there is an 'inband duplex' possibility where the 70cm frequencies are 5 MHz spaced, e.g. TX on 432.678 and RX on 437.678 MHz.

    (afaik nobody uses that option)

    Once you operate simplex you don't want to switch to duplex but that seems to be a 'religious' topic and I'm almost banned from Earth concerning my point of view ; -)

  • The problem with simplex operators is that they cannot hear that they are at a disadvantage when compared to duplex operators.

    E.g. I heard a QSO where I think 4 operators were in a roundtable, and two of them were operating simplex.

    Due to the delay (and therefore uncertainty that they transmit on a clear channel) they were constantly doubling with others, and the duplex stations had to backoff all the time (of course they could hear when they are doubling).

    This is also apparent when calling to "rare stations" on the satellite. Those simplex stations are all transmitting on top of eachother where a duplex station can hear that it is useless to continue shouting.

    I think it is part of the personality of some people to not bother about such things.

    It is likely inherited from the (also simplex) world of DX'ing where it only counts to make that "you are 59" QSO. And some people just want to have the microphone all the time and do not want to be bothered with others who want to say something too.

    However, those that want to listen to others and want to open themselves up to experiences made by others quickly find the advantages of having duplex capability.

    Alas, not all people are like that.

  • Hi All, I ordered the fully solution from PE1CMO and I'm keen to test "simplex" operation over the OSCAR-100. You can still listen on the WebSDR as backup/control.

    As soon I got it, I will let know my expierence.

    73 de HB9RYZ


  • Hoi Andreas,

    i also was one of the first who got the CMO-box. Very nice thing to have, end less cables to be used compared to my other setups. Only used it in simplex mode, not having any problem yet. I have no problem on working simplex, because with my 'normal' setup i cannot hear myself neither. FT-817 in SPLIT mode with front-bnc conn for uplink 144 IF via transverter+ rear-N conn for dwnlink 439 via modified octagon board.

    Also FT847 is used in duplex mode, but pff. The FT817 method or CMO-box is preferred here.


  • I have ordered the simplex version from Rene along with the PA3FYM dual band feed and two power supplies. It is all ready and I expect Rene to ship it this coming week.

    I noticed that Wolfgang HB9RYZ has two versions of his configuration. One is simplex (70cm up and down) and the other one is full duplex with 2m for the uplink and 70cm for the downlink.

    Rene did not recommend this second version to me so I am going with the simplex version all driven buy my sparkling new IC-9700. I have a Leo Bodnar dual GPSDO which will sync it all together.

    I am putting up a 1m offset mesh dish here in the UK as soon as the equipment from Rene arrives.

    I have a couple of questions for the group. How critical is the placement of the all-in-one transverter in respect to the dish? Could I get away with siting it say five or six metres from the dish? The dish will be just outside my shack on the wall (hopefully) and I would prefer to keep the transverter inside the shack rather than in some kind of weather-proof box outside.

    What cable should I use between the PA3FYM dual band feed and the transverter?

    I am going to use a (very short) piece of Ecoflex 15+ between the transverter and rig.

    Thanks and very 73 to everyone! David G4NRT

  • G4NRT I don't know if you ordered the 'full Monty' , i.e. the transverter built in a waterproof box etc. I am not fully aware of Rene's options, but I know he made a separate 739.5 --> 144 MHz converter on specific request for somebody. (I know because I had to write the software ; -)

    Concerning the cables. Rule of thumb on microwaves is that one should keep the cables as short as (practically) possible. Depending on the size of the dish you have some power reserve. E.g. if you use a 90cm (wide) offset dish, 5W at the feed is more than sufficient, meaning you may loose 15W in the feed cable provided the end stage delivers 20W.

    In the Ecoflex 15+ datasheet I read that the attenuation is 14.9 (say 15) dB @2400 MHz, so -6 dB requires 40m of this cable. In other words, 5 - 6m of cable from the TX-connector to the dish will not be a problem (and requires you need to back off your power, depending on the dish size of course).