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HLA 300V PLUS 1.8mhz and up. Is this any good?
- Thread starter Mudduckmobile
- Start date
Same here. I have amps all over the place and most of them work but have never used them, ever. Good transmitter and good antenna make a good station if there is a good operator on the mike.
What makes them a CB amp and make no mistake that's what they are under the disguise is what is at the heart of them once the filters & protection are stripped away,
both the hla150 & 300 are the same amp as the kl400 & kl500 cb amps with extras,
they originally claimed the same crazy output numbers as the cb amps, about 2x what they will do flat balls out or 3-4x the clean output capability.
gain increases significantly as you move down the bands,
RM did nothing at all to improve gain flatness over the CB amps,
they use the same resistor/capacitor feedback networks found in their CB amps not LCR networks to tame the rising gain you would expect to find in an amateur HF amp,
they used the same high gain sd1446 transistors intended for class C vhf service as their CB amps,
they use the same unregulated untracked biasing as the CB amps
the amplifiers are not unconditionally stable like a decent hf amp, not even close,
the sd1446 amps can self oscillate with no provocation at all on SOME frequencies,
the filters can't filter out the high levels of imd no matter how many chips you use to switch them in & out,
what RM did was take CB amp circuits they already used and were known to work on HF & added fancy bits to make them look like a proper HF amp,
so long as you don't look with your eyes open or drive them to anything close to what RM claim for output..
both the hla150 & 300 are the same amp as the kl400 & kl500 cb amps with extras,
they originally claimed the same crazy output numbers as the cb amps, about 2x what they will do flat balls out or 3-4x the clean output capability.
gain increases significantly as you move down the bands,
RM did nothing at all to improve gain flatness over the CB amps,
they use the same resistor/capacitor feedback networks found in their CB amps not LCR networks to tame the rising gain you would expect to find in an amateur HF amp,
they used the same high gain sd1446 transistors intended for class C vhf service as their CB amps,
they use the same unregulated untracked biasing as the CB amps
the amplifiers are not unconditionally stable like a decent hf amp, not even close,
the sd1446 amps can self oscillate with no provocation at all on SOME frequencies,
the filters can't filter out the high levels of imd no matter how many chips you use to switch them in & out,
what RM did was take CB amp circuits they already used and were known to work on HF & added fancy bits to make them look like a proper HF amp,
so long as you don't look with your eyes open or drive them to anything close to what RM claim for output..
