Ed and Dave,
By all means NEVER pay full price for anything. This is the ham motto, still
to this day...
Conversion of anything to anything means that I am tired of soldering,
cutting holes, buying knobs, chassis, and meters, etc...
Someone should have told me this while still a pre puberty ham... But I
lament...
This Mitsubishi DA-A7DC stereo amp came from the dump and I don't know why.
It was cosmestically pure and even seemed to work, but I yanked all circuits
and boards from the inputs to the final transistors and laid in a very
standard circuit made of toroids, IRF PF50 power FETS good for 900volts @
6.7 amps each for cheap e-bay prices...
Using a network analyzer of any sort helps out with tuning the thing as you
can substitute a resistor for the FET, look backwards and come mighty close
to F-sub-O and Z of your tank circuit. Following standard engineering rules
to effectively eliminate harmonics is worth the time also as well, and use
series C/R loads and ferite beads to keep the VHF stuff from happening in
the first place.
This stereo ( now MONO ) amp just makes power @ 100W all day with key down
and no fan, thanks to whomever threw this thing away @ the dump. The power
supply is a LOT more than I needed with 50volts DC @ about 8+ amps
available. I use the 50V and 2 amps, the single stage PP amp only takes
about a watt to drive giving me about 13db of conservative gain with plenty
of head room. Watch the Z of your windings, turns ratios... I am NOT on a 50
ohm standard, but only what it takes to get to the grids of the SB600M (tm)
pair of 572Bs that barely show redness on the plates at full throttle of 1KW
input.
And those GIANT heat sinks on the stereo amp just begged to be filled with
efficient TX FETS too... This driver alone was copied all over the same DX
places as with the afterburner ( SB600M ), only weaker...
And don't scoff @ the dump thing... This week brought a gleaning of 400'
feet of brand new Andrew 1/2" copper hardline, just what I was looking for
to add a parasitic loop to the near field of this one making effective 'R'
go more towards ZERO in conformity to Bill Ashlock, WE2XGR/4 loop theorum...
As for the transverter transceiver, this old beat up IC706A is still
slugging away, and in another life was used as a baseband all mode
transceiver from 2M to 10 ghz. I found a way to accrurately set the QRG with
a Jew's harp or harmonica to within a few HZ @ 10.368 ghz. It was too simple
to understand at first... hihi So now the 706 has literally transceived
from DC to light, thanks to ICOM for the baseband radio...
The same IC706 was also used @ 474 thz. ( laser ) for some long haul QSOs
and cloud bounce, but that was much simpler than with the 10ghz.
transverter, namely by literally placing a laser diode on the antenna
connection of the transceiver, DC biased accordingly and coupled correctly
made for some fairly decent all mode laser transmissions... Same thing for
receive... I couldn't believe it... Like Eureka!!
If you can't 'open' the Electrocraft @ 10 mhz. then use a ham band IF that
you like, such as starting @ 3.5 mhz, then by the time you get to 4 mhz, you
are all set for 0-500 kcs. Or even 28 mhz which will allow you to go from
0-1.7 mhz. the Electrocraft is a shoe in for this kind of use...
As for Mini-Circuits, here is the web page that you can see all sorts and
parameters of any circuit including pricing which I drooled over for weeks
before placing a giant order for a big box of 'plug and play' parts... This
was in conjunction to a project of making a $65,000 dollar Agilent VNA which
works from 50mhz. to 40 ghz. work all the way down from the low limit of
50mhz. to about 50 khz....
The latter project had me buying the really MINI small units and then
stuffing them in a very small professional case a little larger than the
size of a pack of butts...
Try Mini Circuits, but look on e-bay first>>>
http://www.minicircuits.com/sitemap.html
You can also find a bucket of various type mini amps on e-bay as well...
Too much fun for my limited BW...
BTW, how did that Efratom Rubidium Reference work out for you? Is it fairly
quiet in close to the carrier??
TNX from Dave @ 17
Dave,
You are doing with your IC-706 what I have been thinking to do, only I
hope to acquire a Elecraft K3 in the fall. With it I would have separate
Rx and Tx antenna connections and the low power xvtr Tx output as standard
features, so I could dispense of one RF splitters. I recently acquired
one of the Efratom Rubidium Reference Oscillators to provide me with very
accurate 10-MHz for my station. I think I could obtain +10 dBm to drive a
mixer from the 4-way DEMI 10-MHz distribution amp that will take the
Rubidium signal and route to several items in the shack (including the
K3).
Could you send me the Mini-Circuit part numbers of the system you built?
I guess the only other issue would be to convince Elecraft to modify my K3
to transmit 10.100-10.510 MHz.
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