Help with High SWR issues please

I’m as green as it gets, just passed my general & extra license test but honestly know very limited about HF and the hobby.

My Problem: High SWR (Between 5 & infinity on my FT-710 internal SWR meter)

Called Yaesu technical support (talked to Harry) for help, I was told I need to address antenna’s resonance (whatever that means) issue. He said there’s nothing wrong with my FT-710 transceiver.

Current Equipment: Transceiver: Yaesu FT-710 AESS

Power Supply: Pyramid Model-PS-52KX. Also powers IC 2730, KG-XS20G & FT-710. I only transmit one radio at a time. I have another 25 Amp power supply if you recommend me to isolate the radio to a single power supply instead of the current sharing set up.

Antenna: Harvest Taurus 80M – 6M End Fed with 9:1 Unun (SO 239 for coax to transceiver, butterfly connector for wire antenna and another butterfly connector for ground); antenna wire length 64 feet; Max Power 400W; Freq 3.5Mhz; Max Voltage 40V. I also have another Harvest Taurus 40M - 6M end fed antenna with Unun still in the plastic bag (brand new) in case you want me to use it instead.

Coax: RG8X mini; 25 feet with PL259 at each end. One end connected to Unun SO239, other end connected to SO239 on transceiver.

Ground Wire: 10AWG; 25 feet to 18” ground rod (½” diameter)

Ground Rod: Mokikuba portable ground rod (bought from Amazon) 18" long, 1’2" diameter, solid steel shaft with zinc finish.

Current Setup Description: 25 feet of Coax routed from transceiver FT-710 SO239 out to Unun box SO239 mounted under roof eve (side of single story home – height of the Unun box and antenna wire approximately 8.5 feet from the ground). Wire routed under the eve from the Unun box approximately 34.5 feet in length horizontally to end of eve (to backyard) then hangs down then up (approximately 12 feet horizontally) to first tree branch. Then straight up to second tree branch approximately 17.5 feet high.

What am I doing wrong? Any ideas, help or suggestions would be extremely appreciated. I like to learn and truly open to criticisms.

Quickly reading your description. Is the run under the eave in close proximity to metal?

The radiating wire should be kept away from any metals.

73

Bill

W4WCS

Thank you for your response Bill!
I don’t know if the wire is close to metal, the eve is painted. Can’t see if there’s metal close to the wire.
Would it be better if I laid the wire on the ground (horizontally on the ground about 35 feet to wall which starts the backyard), then go up in an angle like a sloper (to about 18 feet high) to the second tree from the ground?
Let me know if that’s something better to try. If you think it is, then I’ll go do it.
I see rabbits &/or quail sometimes meandering around the neighborhood. Hopefully they don’t decide to munch on the wire if laid down on the ground.

Best Regards & 73,

Rene
KD6THZ

If the eave is made of vinyl. You are probably ok. But it could be aluminum. Since you hung it up there. I assume you can check to see if it is in fact metal or vinyl.

Definitely not on the ground.

The best situation would be to run the radiating element away from the house as it exits the UNUN.

If you like contact me by email.

billnopic@yahoo.com

billnopic@yahoo.com

73

Bill

W4WCS

Best thing I can tell you is study up on how to properly tune the antenna without a tuner. That means adjusting the length of the wire to get the swr down. Do your homework@

Don’t lay the antenna on the ground! Antennas belong up in the air as high as you can get them and in the clear away from ground and any metal. Then you have to adjust the length of the wire to get the swr down to a usable range. I assume you took the license exam and some of this should have been covered in the material on the exam.

Thank you Bill, I will try your recommendation.

Best Regards & 73,

Rene

| W4WCS Basic
September 6 |

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If the eave is made of vinyl. You are probably ok. But it could be aluminum. Since you hung it up there. I assume you can check to see if it is in fact metal or vinyl.

Definitely not on the ground.

The best situation would be to run the radiating element away from the house as it exits the UNUN.

If you like contact me by email.

billnopic@yahoo.com

billnopic@yahoo.com

73

Bill

W4WCS

Are you using a tuner with that random wire antenna?

Thank you for your response K4CKR. No. tuner used.
The FT-710 has an internal tuner. However, according to Harry (Tech Supp from Yaesu) the SWR is too high for the internal tuner. Have to fix antenna problem/issue.
I have an MFJ Versa Tuner II but I prefer not to use it because it only makes the transceiver think it’s matched to the antenna even if it really is not. The output power may not even be close to transceivers out power (100 watts). Please correct me if I’m mistaken. Like I said, I’m really new to HF (green).

Best Regards & 73,

Rene

Use your external tuner. If you’re concerned about loss, get a resonant antenna.

Thank you!

Yahoo Mail: Search, Organize, Conquer

Can you please kindly recommend a resonant antenna that conforms with quick to report neighbors and a strict HOA?
Thanks in advance.
73,
Rene

Yahoo Mail: Search, Organize, Conquer

Mount a hamstick on a vehicle and run a coax to it. (Don’t drive off with the coax connected.)

I suggest you use your external tuner with your end-fed before you make any changes.

Hi Rene @KD6THZ

I am surprised that it is possible to pass the extra exam without subsequently having the knowledge to independently locate the fault of a high SWR.

So my proposal is:

I would start with some tests with a Dummy Load :

  1. Place the Dummy Load at the TRX where you would connect the coax cable. So you can check, if your TRX is all right.

  2. Connect your antenna cable to your TRX and place the Dummy Load at the other end of the coax cable. So you can check, if also your coax cable is okay.

Afterwards you know, that the problem is definitly at the antenna. Then note all the helpful tips you have already received from others.


If you don’t know what a Dummy Load is, see explanation video on UT:

73 Pepe

.

:backhand_index_pointing_right: edit: I’ve linked a better explanatory video.

Hi there,

Welcome!

When you read the manufacturer’s description, it says, “Ideal for 80-6m and when used with a good ATU, a perfect match can be obtained on all bands.” So, I think your easiest solution is an eternal tuner. Check out the MAT-TUNER MAT-Y200.

Since you live in an HOA, your front yard needs a flagpole. Look for flagpole antennas on Google.

73

Andreas-KL5PF

Thank you Andreas - KL5PF
A bit on the expensive side for me though ($249.95 @ DX Engineering).
However, still better than having an FT-710 to just listen to others transmitting.
Be working on the antenna to resolve the mismatch with transceiver but will keep your suggestion in mind as an option.
Thanks again!

Best Regards & 73,

Rene

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