Is this the worst antenna for portable use? - Comet HFJ-350M Toy Box

I’ll be right behind her if she needs help!

 

I still disagree on point #2. I maintain that a purely resistive circuit, in other words an ideal 50 Ohm resistor, with no stray reactance to cause self resonance, by itself, is not a resonant circuit.
Please tell me how such a resistor, alone, can resonate.
Unless I'm misunderstanding what you wrote.

 

The debate was that a dummy load (aka a resistor) was resonant at all frequencies. A resistor is usually modelled as a resistor with an inductance in series and a capacitance in parallel. Hence my remark that Xc could not be equal to Xl and zero. If Xc would be zero, the resistor would be shorted.

 

And that is called resonance, which does not occur in a purely resistive component. Therefore the a perfect dummyload is not resonant on any frequency.

 

I was referring to a resonant circuit with discrete L, C, and R components, not a lone physical resistor that has lead inductance and stray capacitance.

 

I think the sticking point between us is that I never described a 50 ohm resistor as a "resonant circuit". All I was pointing out was the circuit equivalence at resonance. I know it's a subtle point, but it is an important one in the understanding of RLC networks.

73 de W3PX

 

That's not treu. your radio want to see 50 OHM the dummy load is 50 ohm . That says nothing abouth the pattern of the antenna

 

Lighten-up, Francis.

 

OBVIOUSLY YOU HAVN'T USED LADDER LINE

 

THE TUNER ISNT REALLY GREAT WITH A COAX(UNBALANCED) FEED IT WANTS RESONANCE WITH THE COAX, LADDER/WINDOW LINE IS (BALANCED) THE TUNER ISNT USLESS AT ALL, MY 560 LOOP IS A KILLER ANTENNA ON ALL HF BANDS FED WITH HOMEMADE LL 600 OHM. THOSE PEOPLE WHO SCOFF AT TUNERS NEVER PLAYED WITH LL AND DIFFERANT (NON-RESONANT) ANTENNA. THEY HIDE THIS STUFF IN BOOKS

 

LOWES AND TRACTOR SUPPLY

 

Yes i have and it was a load of crap..never again..

 

I'll stick with my monoband antennas if that's ok with you..

 

Nope. Anything that conducts RF power is antenna. Good or surrogate, whatever. Radiation of an antenna does not depend on resonance but on current distribution in it, and losses caused by resistivity of real counductor, of the ground (where applicable), and so on. Radiation/losses ratio is measure of antenna efficiency.
Dummy load has almost 100% losses (intentionally) so it has steady impedance within its working range. Obviously dummy load would appear as resonant antenna on any frequency so useless for tuning the amp for a real (imperfect) antenna at given frequency (where particular impedance may vary).

Matching may be wanted due many reasons but this doesn't mean the antenna itself has to have resonance to radiate efficiently. Sure one can tune rusty nail and call it 'antenna' but its efficiency is still radiation/losses ratio, not the resonance.

 

An end-fed half wave is way less expensive and easier to use.

73,
Pete