construction of the final stage 50w to yaesu 817

Home Forums CQ HAM forum Projects, Mods, Fixes and Add-on's construction of the final stage 50w to yaesu 817

Viewing 13 posts - 1 through 13 (of 13 total)
  • Author
  • #11388 Reply

    I bought irfz44n 94w transistors, one transistor, I don't know how much I have to excite it to get at least 50w at 12v, or even what output stage, I don't know if it would be 2m + 70cm breed

    #14067 Reply

    A friend, what if instead of building antennas and PA, he preferred the study of the Slovak language? Maybe you don't know, but you present yourself with your speech.

    #14068 Reply

    ERIK5553, you can't handle the PA construction, I am based on your post:
    You can also read something about YAESU here:
    Send the post like this, that you read it after yourself, you click on “Insight”
    and only then did they send him away!

    #14069 Reply

    the final stage is not a problem for me, I can read the chemistry scheme as well blank do not cause any problem

    #14070 Reply

    “I can also read schematics” – you made me laugh quite a bit my friend 😀
    And you can (and you have something) and measure? 💡 ❓ ❗

    #14071 Reply

    If you could really read diagrams, so you don't ask here what power to wake up the PA and on which bands it will work.

    #14072 Reply

    Postavat VF zosik ku FT 817 it's a bit of a religious order.
    It also creates a problem for an experienced designer, because the problem of signal purity of the station itself must be solved first, the edits are on the internet, but they are not quite simple, as simple as it seems at first glance.
    These are primarily ALC circuits

    After that, the second phase is filtration after HF PA, which is also not simple.

    A bunch of ready-made amplifiers for HF bands solves it perfectly, without possible failure.
    The second problem is the price..

    They will buy a bigger TRX type FT 857, or 897, or other TRX yamcomwood from second hand or ebay and so on. less will come out, if he bathes, or HF PA production “small performance” which factory manufactured transceivers have as a basic performance.
    It is different from the highest power over kW, but again it's a question of price, because cheap Ameritron from 4x 811, or 4x 572B costs less, as he strives for home construction and hunting for parts, which are not easily available, but there is a long way to go.

    Simple TRX all band for the car and FT for the portable 857, or FT857D, for power supply, a assembled battery of LiIon cells is enough, it's not bigger than manpack trx and it's all mode, from 160m to 70cm
    Priced secondhand prices around 350-500eur, it is not possible to produce a similar apartment only with HF PA and adjust it to the FT817+HF PA system

    FT 817 is quite a specific device, probably the most miniature and compact device, which still has no competition on the market.
    Its big plus is the built-in source and absolute QRP portable design.
    But it is definitely for very advanced amateurs, who know how to construct antennas and possibly use F817 as a driver for various transverters and similar miracles.
    I mean, that even the Vertex Horizon/yaesu manufacturer does not recommend connecting the FT817 to the HF PA in the product specification.

    Zial lacquered design and minimalist absolute ALLMode lacquer for beginners and few experienced hams to buy it and another torture of problems follows.

    Otherwise, considering the price of the FT817, which is not low at all, can also be found for 2/3 ceny FT 817 same “full power” all mode 100W(VHF 50W, UHF20W) but the designers and designers built on the success of the 706 and did well, pocnuc FT100D, az po FT897.

    But don't throw stones at me, I still use FT817.. 😯

    #14073 Reply

    Ron, no one will throw stones at you, because you are right in almost everything 🙂

    For FT817 but also for 857 a 897 treba is added, that it is necessary to tighten the kludge currents according to the documentation and at least once in a while 2 years according to my experience, otherwise the modulation is choppy and the signal does not do well in the surroundings 🙂
    I use FT857D for SOTU, with ALC administrations, DTMF with microphone (electret + radio control). For signal purity, the DSP is suitably bypassed on the FT857D and 897D, because what DSP produces for very close SSB stations is des, Dodo describes it as an electrical screeching in a turn 🙂 The DSP produces a faint screeching sound, which without modulation for a station 1.5 km away means approx. S6 interference at the working frequency without modulation and it does not matter if the power is set to 5W or 100. DSP for TX bypass is available directly on the PCB (preparation for old stations without D). It is also important to have a solid source of voltage, Lion is excellent, PB too, but they must have thick cables and good connectors, otherwise the signal is very poor, again personal experience with Chinese connector for FT857, which mechanically did not suffer at all.

    K base, I tried to connect a cheap CB amplifier to the FT-817ND for the idea of ​​weight reduction. There are 4x mosfet inside and it was usable from 20m to 10m (into an artificial cloud), although it also worked on 40m, but the adaptation at the entrance was already bad. It gives approx. 60W on FM/CW when powered by 3cl. lipo. But the amplifier does not contain any output filter, I found a dock for it and also a conversion kit for it, it is necessary to replace the input transformer, complete the stabilization of the voltage for cludky currents and solve the output filter. It is also convenient to solve the RX/TX switching using a cable from the radio, VOX on SSB is not much, when it switches after a second. The problem, however, remains the necessity of a low PSV, otherwise there is a risk of destruction, there is no protection. I threw in the FT-857D with a microphone and battery and a set of FT817 with a microphone, batteries, kablikami, a difference of 630g in favor of the FT817. Po uvahe ale stavam pri FT-857D, he will also survive maladjustment, has high performance even on 6m and 2m and fewer connecting cables, which can cause a problem. FT857D is also a bit lower in RX and even the DSP can make the operation a bit smoother.

    #14074 Reply

    OM1ARH: those lines have one problem. They mostly deal with the older version, and the newer version has some things done a little differently.

    I also wanted to adjust the ALC on my FT817ND and discovered that it might not turn out well.

    And what about the purity of the signal coming from the FT817. it is true that it is not the cleanest, but more or less all modern constructions suffer from this.

    And as for why Yeasu doesn't make a zosik for FT817, the reason is some regulation of the American FCC. They have it in the FAQ

    #14075 Reply

    Unfortunately, I have no experience with the ND and D versions, I only own older devices from vl. imports such as FT 857 without “D” and I recently sold an older FT type 817 without “Peter KA6U activated last year during the summer”
    My experiences come from these devices, the last of the year 2007.
    I used to use the FT100 for a while and I'm less familiar with it, or the Vertex portable flashlight VX-1210, which is no longer mine.

    #14076 Reply

    Founded: Feb 01, 2010
    Replies: 11
    Residence: Confusion

    PostSent: 21 Apr, 2013 4:19
    Case: Reply with a quote

    I would like to write down the tests, how long they take when I learn them, so that I can learn them later 3 months.
    from April 21 2013 I guess it's already more than those three months, what did you write that you will take the exams?….it is already after the harvest.
    😀 😆 😯 …… 😥

    #22080 Reply

    moli to moje ked som si chel vytvorit pa k ft 817nd pablank

    #22084 Reply

    AK vieš čítať schémy tak v tejto je uvedené, že na výstupný výkon 50W PEP je potrebný budiaci výkon 1,5W, inak schéma je to jednoduchá a funguje ok…..73 OM1DS

Viewing 13 posts - 1 through 13 (of 13 total)
Reply To: construction of the final stage 50w to yaesu 817
Your information:

33 + = 35