Base Holy Wideband!!

[Shadetree Mechanic]

Spur at 54 mhz? What's this in layman terms, noise or ...

 

[Greg T]

I don't see mention of the antenna. Your low swr bandwidth could be good, and it could be bad. Without knowing what antenna you have I don't know what bandwidth to expect.

I gotta cheapie Sigma Silver Rod 5/8 wave.

 

[Greg T]

This is all true. But I am confident that my Yaesu is not a splatter box and the signal going INTO my filter is already clean.

 

[Keto]

Great info, and very interesting that that's how you can get some television interference, or at least they did in the past. 54 MHz Spike. Thanks @Shadetree Mechanic

 

[Greg T]

Okay, couldn't do a video because of cramped quarters and needing both hands on the radio and shit, but I checked the band width and can go from 26.775 to 27.795 and stay within 1.5:1 on both ends.

 

[groundwire]

I gotta cheapie Sigma Silver Rod 5/8 wave.

View attachment 41396

Look at those little ground plane radials lol, how cute.

 

[Greg T]

Look at those little ground plane radials lol, how cute.

Yeah, pretty useless. But, I'm hoping to extend them to 108" if I can find light enough material. Some time next summer

 

[Shockwave]

Yeah, pretty useless. But, I'm hoping to extend them to 108" if I can find light enough material. Some time next summer

That will change the impedance, resonant frequency and VSWR. You may be able to compensate for that with the radiator length, but this antenna has a sealed matching coil that does not appear adjustable if needed.

 

[Dmans]

Maybe it would help to list my rig. I have a Yaesu FT-990 going into a TS DX-500V, going into a meter going into the filter going into the antenna.

Maybe try putting the filter between the FT-990 and the amp? If the FT-990 sees even the slightest bit of mismatch or SWR it could create a harmonic or 54 Mhz spur. Why amplify that harmonic?
Garbage In=Garbage out!

Just my unsolicited 2 cents.

73
David

 

[Greg T]

Maybe try putting the filter between the FT-990 and the amp? If the FT-990 sees even the slightest bit of mismatch or SWR it could create a harmonic or 54 Mhz spur. Why amplify that harmonic?
Garbage In=Garbage out!

Just my unsolicited 2 cents.

73
David

There is no mismatch between the radio and amp. Flat match without tuner

 

[Greg T]

That will change the impedance, resonant frequency and VSWR. You may be able to compensate for that with the radiator length, but this antenna has a sealed matching coil that does not appear adjustable if needed.

I'm sure there's a formula somewhere to figure it out.