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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