Kevin Schmidt, W9CF, has a nice Java app where you can study the losses
in a T-network tuner at http://fermi.la.asu.edu/w9cf/tuner/tuner.html
Tom W0VJ
On 5/4/2012 7:22 AM, Carl wrote:
> The first series of tests even had the MFJ coils catching on fire in the
> ARRL lab at well under power ratings on 160.
>
> Tuners with 250pf max on 160 will always be inefficient, a High C tuner with
> 500pf will be very efficient and require proportionally less L. The higher Q
> results in less bandwidth so there is no free lunch.
>
> Its so much easier to modify an amp to be able to do the matching and toss
> the tuner in the dumpster.
>
> Those with autotune amps are left swinging in the wind and need autotune
> tuners (-;
>
> Carl
> KM1H
>
>
>
> Carl
> KM1H
> ----- Original Message -----
> From: "Roger (K8RI)"<k8ri@rogerhalstead.com>
> To:<amps@contesting.com>
> Sent: Friday, May 04, 2012 3:32 AM
> Subject: Re: [Amps] Antenna tuner loss
>
>
> On 5/3/2012 12:32 PM, Dan Hearn wrote:
>> ARRL tested some popular commercial antenna tuners and reported the
>> results in QST as follows. They covered 160-10 and various loads. All were
>> quite lossy on the low bands with low Z loads.
> And there are people out there that didn't expect this? They are
> running into low impedance loads which means high currents and high
> losses. I believe the Palstar manual even mentions this. Also the
> power handling capability drops off substantially with low Z loads
>
> 73
>
> Roger (K8RI)
>> February, 2003
>> Product Reviews
>> High Power Antenna Tuners:
>> • AMERITRON ATR-30
>> • MFJ-986
>> • PALSTAR AT1500CV
>> • TEN-TEC 238A
>> • VECTRONICS HFT-1500
>>
>
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