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Power Output Problem On Yaesu 450D? Need help.

Discussion in 'General Technical Questions and Answers' started by K5BRY, May 5, 2012.

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  1. K5BRY

    K5BRY Premium Subscriber QRZ Page

    I just received a Yaesu 450D and I have a problem. I'm using it with a G5RV Jr., strung across the top of a six foot wooden fence. I can set the power output to 100 watts and set the Dim Meter on PO for power output. I pushed the 'Tune' button so the ANT diagram is blinking, meaning the internal tuner should be on and working. When I key down, the Power Output meter doesn't even go to 1 on the meter and my power supply shows I'm barely using any amps. I'm guessing this means that Im' not transmitting for some reason. I hooked the antenna up to an SWR meter and it barely moves the dials, which I'm assuming means I've essentially got no output. I know the internal tuner on the 450D will only work for SWRs less then 3, but how do I know that's the problem?

    My question is, has the radio shut down transmit for protection for some reason (High SWR), or do I have a problem with transmit on my new radio? Any way to tell?
  2. K0SPN

    K0SPN Ham Member QRZ Page

    Depends on the band, but a G5RV will have a higher SWR than 3:1 on some (many? most?) bands.
    Sounds to me like it's limiting itself. When you push the tune button do the relays click once or twice then stop while the antenna symbol keeps blinking? If so then it's outside the 3:1 spec.
    The relays normally click quite a few times (like 5 seconds worth or so) while it tries different combinations to match the impedance.

    Get a dummy load and test it with that.
  3. K5BRY

    K5BRY Premium Subscriber QRZ Page

    On 20 meters, yes, the relays kick on and then after a few seconds the antenna symbol stops blinking. But on 40 meters, the relays don't even kick on.
  4. K0SPN

    K0SPN Ham Member QRZ Page

    Right, that's because on every band besides 20m, the antenna has a SWR of more than 3:1, which the internal transmatch cannot match.
    You need an external matcher for a G5RV to be used on bands other than 20m.

    Also, you say:
    If you're using SSB, then you won't show any output power because there is none when you aren't speaking; thus the power supply would show minimal current draw as you'd only be using about 1-2 A more than receive since the PA isn't 'doing it's thing', as it were.
    If you were in CW mode and keyed down you would have full output and power draw, which would be around 18-20 A.

    No offense intended, but it appears you're new, so I'm just guessing you don't (or didn't until now) understand the power draw when in SSB mode nor have much info about a G5RV other than maybe hearing something like "it's a great all-band antenna", so you bought one from somewhere not knowing that you'd need an external transmatch.
    I'm also just guessing that you were using SSB mode, as most people don't know Morse code when they first get licensed now.

    If I've gone wrong somewhere with my guesses, let me know and maybe you really do have a problem and we can figure it out.
  5. K5BRY

    K5BRY Premium Subscriber QRZ Page

    K0SPN -- You're right, all of this is new to me. I passed my technician license in February and my general in March. I just got my first HF radio (450D) yesterday. Now that you mention some of this, I remember reading about the power draw on SSB when I studied for the license exams. No offense taken here and I very much appreciate your help. I'll make my way down to the local radio supply store today to look for an antenna tuner.
  6. K8JD

    K8JD Ham Member QRZ Page

    f you set the rig for CW and have it set up properly you should see your full output when you press your key down ( NOT your mic button) then read SWR. Run the intertnal tuner and I suspect things will work ok. Read your manual Cover-to-Cover a few times.
    Have fun>
  7. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    Ham radio never dumbed down, not at all.:eek:

    I'm trying to imagine any ham in the 1960s not knowing you have to modulate to create output power on SSB, but try as I might, I can't think of any.;)

    It's all good.
  8. NA0AA

    NA0AA Ham Member QRZ Page

    Steve, it's easy to look down from years of experience and say that. <grin>

    I'll bet that like me, you probably had a real elmer too, right?

    Hey OP: No harm done, but while you are at the Ham store, buy the ARRL Antenna book, and maybe an in-line SWR meter. You have lots to learn about antennas, and reading about how they work is a good way to start.

    Another thought, if you decide to buy an auto tuner I suggest you buy an LDG, their AT-100Pro and 200Pro [may now be Pro 2's?] are excellent and will work with ANY radio you buy in the future. When you 'tune' with any auto tuner, you turn the power down and use AM or CW [that saves you having to whistle for 5 seconds into the mic] then switch back to SSB and talk - these smart tuners are great as they learn your antennas and re-tune very quickly. I've had nothing but good experiences with the LDG products.

    AND, lastly, if you want that G5RV to work, you are going to have to actually get it up in the air a ways - it's ok to do an inverted V - just get the legs spread out about 120 degrees if you can, center up 30 to 35' and you will be astonished by the difference.

    Do you belong to your local club?
  9. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    Nope. My "elmer" was the Public Library, and a lot of those books referenced engineering texts that weren't at the Public Library, so I rode my bike to the engineering library at NCE (now New Jersey Institute of Technology) and as a visitor I couldn't check out a book, but I could sit there and read them. And I did that, probably once or twice a week. The bike ride was 9 miles each way, and my parents never knew.:eek:
  10. KB5HAB

    KB5HAB Ham Member QRZ Page

    When you say you pushed the Tune button did you hold in pushed in for a second or so? A quick push only engages/disengages the tuner and it may be sitting on an "older" tuned position which is not correct for the present setup. Try pushing and holding the Tune button for at least a second and it should make some steady noise for a couple of seconds while searching for a tuned condition. Now if the antenna icon is flashing the tuner could not match the antenna system and the rig may not transmit.
  11. KO6WB

    KO6WB Premium Subscriber QRZ Page

    Another valuable piece of equipment to have is some type of dummy load that can handle the power you will be running in the future. An external SWR or a good power meter will be handy as well. If you can operate into a dummy load but not the antenna then you know it's not the rigs fault and you can check the antenna. The SWR meter will also indicate the status of the antenna system.
    The G5RV has mixed opinions on how effective of an antenna it is. It was designed for 20 meters and has gain and nulls on that band. Other bands just seem to fit in as a bonus. There have been numerous version of the G5RV made by commerical interests and a lot of them took liberties with the intended design and added length, took length away, changed the matching section, applied baluns and other things. These antennas are technically not a G5RV but are something else. The G5RV can do okay on other bands aside from 20 meters but then again a lot of antennas can make that claim.
    You need to experiment to find out what suits you the best. Read the information on the internet that is from a creditable source. Try to interpet what some of the articles say. If they are stating their antenna is new, that's fine, but if they state further that their antenna works on a principal that existing science cannot explain and modeling the antenna is impossible then quit reading and move to the next antenna article.
    Good luck
    Last edited: May 9, 2012
  12. KA9VQF

    KA9VQF Ham Member QRZ Page

    The original G5RV has a section of ladder line in it that works as a matching transformer. It actually radiates on most of the bands you use the antenna for.

    If your particular version of the G5RV has the ladder line in it and you only have it mounted on a fence 5 feet off the ground you will have to support the ladder line at least that high. By that I mean the ladder line should not be just laying on the ground.

    I'm guessing you only strung the thing up 'quick and dirty' to test out your new rig. Lots of us have done similar things. In a rush to get the new toy on the air. Don't worry about it, but get your antenna as high as you can.

    I sincerely hope you do not have to contend with any CCR's or HOA's, nagging wife/parents and can actually string your wire where you want.

    If you don't have trees or other fairly tall structures handy, you can build simple A frames out of the fairly cheap stud grade 2X4's to hold the wire off the ground. You will need three of them. One taller for the center and two shorter ones for each end. If you already have something for the ends, I used a shed for one end of my first wire antenna, go ahead and use it.

    You will have to put at least one guy wire on each end of the A frames to keep them from blowing over. I used the copper coated steel antenna wire for my antenna and it was strong enough to be pulled tight between the A frames. Later I fell into a deal on a big wad of paracord and used that between the A frames just for a bit more support. I worried that either the ceramic dog bone insulator in the middle or the wire itself would break in the wind.

    I used steel electric fence posts driven almost all the way into the ground at the base of the A frames to keep them in place too.
    The electric fence posts were cheap enough that I used two on each A frame and one for each of the guy wires on the ends.

    It was a bit of a PITA to mow around but,... you'll have that.

    I painted my A frames with alternating red and white bars trying to make it look more like an antenna structure. It helped folks wandering around the yard to avoid them too. I tied red and white cloth pennants on the guy wires to help myself keep from running into them when I would mow.

    They also worked pretty well to tell when the wind was blowing.
  13. K0SPN

    K0SPN Ham Member QRZ Page

    Nice catch. That would certainly be a problem.
  14. WG7X

    WG7X Ham Member QRZ Page

    Since this is "'da Zed", I'll put in my two cents.

    I had the same "Elmer" as Steve. The amazing thing about reading... The more you do it, the more educated you get.

    I'll need a couple more decades to wrap my head around Maxwell's "Reflections", much less "Reflections II"

    Won't stop me from trying though...

    73 Gary
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