Gonset G76

Discussion in 'Amplitude Modulation' started by N2DTS, Jun 4, 2019.

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  1. N2DTS

    N2DTS Ham Member QRZ Page

    I was on 80 last night working Jim, N3JUH after the storm went through.
    About 70 watts carrier, he said I was 30 over and well above the static crashes.
    The radio has all the original tubes (I guess) as they all have Gonset labels, except one 6DQ6 which has an erratic filiment connection.
    Not sure if its dirty pins or something inside the tube.
    The radio puts plenty of audio on the carrier.
     
  2. AF4K

    AF4K Ham Member QRZ Page

    GREAT radio, but OH SO HARD TO SELL! I had a super nice one here with the original manual, and
    advertised it for over 6 mojnths before anyone took any interest, and bought it from me at a very reduced price.
    Sadly hams are losing interest in this sort of thing, unless they JUST GOTTA HAVE ONE RIGHT NOW,
    in which case they go to eBay and pay $2500 willingly!

     
  3. N2DTS

    N2DTS Ham Member QRZ Page

    I would like to find a clean one.
    They seem to sell quickly on ebay, at higher prices then I would expect, but then I am used to getting one like new with power supply for $100.00 at a ham fest.
    You might start seeing that again, its been a roller coaster, first they are new and people want one, then they get old and people want solid state ssb stuff and you cant give one away, then they become vintage just like kids wanted when they were 15, then all those people go into the old folks home and you cant give it away again.

    These are interesting as its a station in a box, at 70 watts carrier, and its not heavy.
    Its quite use-able on the air once it warms up a bit and the vfo gets stable.
    It also seems quite bullet proof, I think its got two electrolytic caps in it, one is not needed (cathode bypass) and loads of ceramic caps.
    I do not think it has any paper caps in it.
    262 KHz IF can give a good response, the main downside is the somewhat quick tuning.

    Its a really nice rig to have around.
     
  4. AF4K

    AF4K Ham Member QRZ Page

    I’m not sure if the 70 W carrier is input or output, but either way that translates to at least 250 W PEP which is amazing for a transceiver of that era in a package so small. In my opinion it was a very underappreciated piece of equipment they should’ve been selling like hotcakes but perhaps the price was tough for a lot of young radio amateurs to come up with. 73 all,
    Bry, AF4K/ G3XLQ, WB4FPH, WN4NRR, A4941
     
  5. N2DTS

    N2DTS Ham Member QRZ Page

    Per my meters, it does between 60 and 70 watts carrier and 200 watts pep.
    The mod monitor shows well over 100% in both directions if you run it that way.
    $380.00 was a lot of money back then I suppose, not sure that included a power supply...
    And I think ssb was well under way.
    For mobile operation, ssb does work much better....


     
  6. WD5JKO

    WD5JKO Ham Member QRZ Page

    Hi Brett,

    I just noticed this thread. I uploaded what I did to my G76. I use this rig several times a week on 75m. I use an external VFO, or a crystal. The internal VFO is not particularly stable, and on the upper bands, the VFO has a lot of FM when modulating the rig on AM. In my case I wanted to add a form of negative cycle loading to the modulator, and be able to hit audio peaks to 140% modulation. This required beefing up the audio driver stage and reducing the plate voltage to the Rf final. I get about 45 watts RF output this way.

    Jim
    Wd5JKO
     

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  7. AC0OB

    AC0OB Subscriber QRZ Page

    Hey Jim, glad to see you! :)

    Gonsets are nice rigs.

    Pheel
     
  8. WZ5Q

    WZ5Q Ham Member QRZ Page

    Pheel, Jim is the one that gave me the idea to use screen driven sweepies for modulators on my AF-67 morphidation.
     
  9. AC0OB

    AC0OB Subscriber QRZ Page

    Gee, if I had known that I wouldn't have said such good things about him. :D

    Seriously, Jim and I go back a few years, with the number of years to be kept out of public view.;)


    Pheel
     
  10. WD5JKO

    WD5JKO Ham Member QRZ Page

    Adding to my post. The RF output of my G76 goes to an attenuator (about 4 db I think), and then to the input of my Gonset GSB201 linear amplifier. I run 4 Russian vintage 811A's with 12V bias (cutoff) for what some call class BC AM linear, Class BC on AM depending on the bias, and drive level will increase the modulation percentage on the output. In my case the RF output from a 180 watt carrier can modulate around 150% positive peaks. I do not splatter much if at all, typically about 7 Khz wide with no audio LPF in the audio chain. Makes for a very effective transmitter setup. Most people say I sounds FB....Many of those Super Modulated setups transmit significant distortion, i.e. W8VYZ audio. Mike, you have heard my rig several times...

    Jim
    Wd5JKO
     

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