G-RADIO1 wrote:
I WILL ALWAYS USE AAREFF NOTHING ELSE AND I HAVE TRYD THE LOTT NOTHING COMPARES TO THE AAREFF TRANSMITTERS FACT
I've
had three of their "200 Watt" efforts here on the bench. They were
bought by someone who believed the hype, and had got a licence for a
Mediterranean island:
None of the three achieved its rated power. Output power into a 50Ω load was between 110 and 135 Watts.
None
of the three produced the same power out at the same frequency. They
were tested at 88MHz, 98MHz and 108MHz. Power varied by about 20% -
higher at the low end of the band.
Second harmonic (at best) was -31dBc. This doesn't meet
any professional specification despite their bogus advertising spiel.
In band spurs were present on all of them at 6.4 MHz either side of the carrier. One of them had spur outputs at only -5dBc.
All
of them hummed and the audio quality was abysmal as well. The
transistor modulator was wrongly biased which caused the audio to clip
in one direction. This is such a basic error that it was obvious the
things hadn't been tested.
All three allowed significant amounts of ½f through.
Standard
tests into mismatched loads (capacitive and inductive and variable
resistive loads) caused the PA stages to burst into self-oscillation,
producing broadband crap from 40 - 250 MHz.
One of the PA devices
fried when run into a resistive load for an hour. Hollings claimed
that the "devices must have been abused".
When Hollings was
confronted about the appalling performance of these heaps of steaming
crap, he made all sorts of threats and refused to take them back as
"unfit for purpose" and refund the money. Several squaddies (who were
going to be the eventual users of the gear) paid him a visit a few days
later, and he found the money to repay them in cash very quickly!
So
G-Radio1, if you want to get yourself arrested for causing massive
interference, go ahead. Hollings will be happy to help with your dash
into a cell. Remember - when the gear doesn't work properly (and it
won't) Hollings will blame you and threaten you if you try to get your
money back.
A quick analysis of the "design" - an inferior copy
of Stephen's driver board. The oscillator is fundamentally
misunderstood, and is out of balance, causing lots of ½f breakthrough.
The "gain levelling" is done by overdriving the exciter output stage.
It will produce the same output on any frequency, but will generate
plenty of its own! The PA was a mess, and looked like it had been
soldered together by a baboon with a blowtorch.....