ad: UR5CDXcom-1

Power Output Problem On Yaesu 450D? Need help.

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

Thread Status:
Not open for further replies.
ad: L-HROutlet
ad: l-rl
ad: Subscribe
ad: L-rfparts
ad: l-gcopper
  1. K5BRY

    K5BRY XML 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 XML 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 XML 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.
Thread Status:
Not open for further replies.

Share This Page

ad: Hamcestry-1