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Alpha 9500 question
- Thread starter The20poundhammer
- Start date
Pretty sure it operates on 11 meters but it will fail if used there for very long. I read about this on an alpha group somewhere & it's the same for most of their amps.
SIX-SHOOTER
W4KVW
WRMX520
Minimal gain at 27 MHz
FCC rules severely restrict gain in the 11m (27MHz) band. This is frequency from 26-28 MHz.
The ALPHA 9500 has a unique design feature which makes achieving useful gain in this
frequency range impossible. At the input of the amplifier, the driving signal is sampled, and this
sample is applied to a frequency counter. The frequency of the driving signal can be determined
to within +/- 5kHz. The master microprocessor compares this frequency with a pre-programmed
table to determine whether to allow the unit to become fully functional. If it determines that the
frequency lies outside the allowable bands, the amplifier remains in Bypass mode, with the input
connected directly to the output. Thus the unit has 0 dB gain. There are a few ranges that are
blocked for purely technical reasons relating to the design of the product. The range 26-28 MHz
is specifically blocked, and the amplifier remains in bypass over this range. The operational
parameters are fixed by programming code and are not available to the user. Since the master
microprocessor is actually the frequency counter, there is no simple way for this feature to be
defeated without severely impacting other functions of the amplifier
FCC rules severely restrict gain in the 11m (27MHz) band. This is frequency from 26-28 MHz.
The ALPHA 9500 has a unique design feature which makes achieving useful gain in this
frequency range impossible. At the input of the amplifier, the driving signal is sampled, and this
sample is applied to a frequency counter. The frequency of the driving signal can be determined
to within +/- 5kHz. The master microprocessor compares this frequency with a pre-programmed
table to determine whether to allow the unit to become fully functional. If it determines that the
frequency lies outside the allowable bands, the amplifier remains in Bypass mode, with the input
connected directly to the output. Thus the unit has 0 dB gain. There are a few ranges that are
blocked for purely technical reasons relating to the design of the product. The range 26-28 MHz
is specifically blocked, and the amplifier remains in bypass over this range. The operational
parameters are fixed by programming code and are not available to the user. Since the master
microprocessor is actually the frequency counter, there is no simple way for this feature to be
defeated without severely impacting other functions of the amplifier
So, yes, it can be modified. You just have replace the microprocesor with one of your own and replicate all of it's functions in the code that you'll have to write. Oh, and duplicate all of it's interfaces to the rest of the amp as well.
I guess you could pay someone to do all that for you. Shouldn't cost more than about 5 or 6 thousand dollars for the whole project.
Reverse-engineering the amplifier's firmware where this restriction resides is possible, maybe. Simply creating your own "clean room" program with no help from the original code would take you at least as long as it did the people who developed it in the first place. They had a reason to make that investment, the profit from selling completed units. And consider how much debugging time they spent once the first version was fired up and tried.
Decades ago, the code for an embedded controller chip was stored in a physically-separate ROM chip you could read back and analyze. We took great pleasure in reading the ROM code, disassembling it and making mods we wanted, writing the modded code to a blank chip and adding a desired feature. These days, it's all crammed into one chip, most likely. Many of them have a copy protection feature. Once the chip's code is written, you can't just read it back using the programming tool. Every PIC chip in a product we sold had the "protect" bit activated.
Kinda like encapsulating the circuit board in your daily driver's Engine Control Unit in epoxy resin. When a two-dollar transistor that drives the single-point fuel injector takes a dump, the cost of fixing the old ECU is vastly higher than the price to replace it. Doesn't make it impossible, just makes it massively unattractive to try.
Even if we theorize 'fixing' the amplifier's code one way or another, who will write the checks to make it happen? With no hope of making that money back, there will be no volunteers.
Any way you go about it, even the cheapest of all the possibilities costs more than you can justify to open up the coverage of one amplifier alone.
No way to monetize the investment, no investors will be interested.
73
Decades ago, the code for an embedded controller chip was stored in a physically-separate ROM chip you could read back and analyze. We took great pleasure in reading the ROM code, disassembling it and making mods we wanted, writing the modded code to a blank chip and adding a desired feature. These days, it's all crammed into one chip, most likely. Many of them have a copy protection feature. Once the chip's code is written, you can't just read it back using the programming tool. Every PIC chip in a product we sold had the "protect" bit activated.
Kinda like encapsulating the circuit board in your daily driver's Engine Control Unit in epoxy resin. When a two-dollar transistor that drives the single-point fuel injector takes a dump, the cost of fixing the old ECU is vastly higher than the price to replace it. Doesn't make it impossible, just makes it massively unattractive to try.
Even if we theorize 'fixing' the amplifier's code one way or another, who will write the checks to make it happen? With no hope of making that money back, there will be no volunteers.
Any way you go about it, even the cheapest of all the possibilities costs more than you can justify to open up the coverage of one amplifier alone.
No way to monetize the investment, no investors will be interested.
73
