Antenna causes distorted signal and higher output on the meter?

[mr_fx]

I built a dipole for 10m running it horizontal one leg of it runs about 3 foot above my roof the other leg is about 10 foot above my deck

It's being fed with some old RG8 I had laying around

the radio put out some where around 45-55 watts and sounds distorted on this antenna

it shows about a 1.5:1 SWR match at 28.415 Mhz


then the dummy load shows about 25 watts out

and the Maco V 5/8 which has a 2.2:1 SWR shows about 25 watts out and it sounds great (Tuned it for CB, just been too lazy to retune it for the HAM bands)

I had another General class HAM record me and play it back, while the dipole sounds louder it sounds quite overdriven

the Maco V 5/8 on the other hand sounds like butter

I really don't understand this...

 

[The DB]

An antenna is a dumb device, it doesn't modify the signal it gets, and by itself will not cause distortion. Even if an antenna is a five inch piece of wire on HF frequencies the modulated signal is still the same.

More likely there are common mode currents in the coax from this antenna and they are strong enough to interfere with the radio. Are you by chance using a balun/choke at the antenna feed point? Also, is the feed line running next to a radiating part of the antenna or is it routed directly away from it for at least 1/4 wavelength or so?


The DB

 

[mr_fx]

An antenna is a dumb device, it doesn't modify the signal it gets, and by itself will not cause distortion. Even if an antenna is a five inch piece of wire on HF frequencies the modulated signal is still the same.

I know, now you can see why I am scratching my head

 

[packrat]

Try turning down the power.

 

[Shockwave]

I agree with DB. Antennas do not cause distortion directly but they can allow RFI to get back in the transmitter and mess with the speech amp or modulator circuits. Choke the coax on the dipole and it should help unless the antenna is just too close to the radio.

 

[Marconi]

Mr FX I think the way you have this antenna installed is a big part of the problem. It would probably work better just laying on the ground. I agree with Shockwave and The DB regarding the common mode currents acting bad in the audio portion or Mic on your radio.

 

[mr_fx]

Try turning down the power.

stock HR2510, no power adjustment, if the power is right on the dummy load and right on the vertical, it should be right on the dipole

well there is an internal adjustment, but that's not the issue here

 

[RatsoW8]

FX- the service manual for the HR25120 shows stock PEP SSB output in the range of 18-26 watts. That's about what mine shows out on SSB. So if you're seeing 45-55 watts on the dipole setup then RF is probably getting back into the radio and wattmeter, Causing audio distortion and the high reading on the meter.

I would suspect bad coax, solder connection or PL-259. It wouldn't hurt to have the dipole up away from the roof either.

 

[WA8ZYT]

Use one of these when you put up a dipole. You will be very pleased with the results.

COMTEK Jerry Sevick W2FMI Series Current Baluns - DXEngineering.com

 

[Marconi]

Use one of these when you put up a dipole. You will be very pleased with the results.

COMTEK Jerry Sevick W2FMI Series Current Baluns - DXEngineering.com

WA8YT, can you tell us a little about your issues with your dipole, and what you experienced that pleased you with this product.

I'm from the "show me something" state.

 

[mr_fx]

WA8YT, can you tell us a little about your issues with your dipole, and what you experienced that pleased you with this product.

I'm from the "show me something" state.

I thought you were from the state where everything was big? I am from the Show me state