Did either 87A require return to Alpha? If so, what were the symptoms?
tnx
>Of course, Alpha's main competitor in this performance and price class is
>the ACOM 2000A. I have owned two ACOMs and two 87As. I
>now run only the older battleship Alphas. Anyway...
>
>Both the 87A and ACOM performed well. At the time, ACOM had not yet
>released their control software and promises were left empty
>for a long time. I believe they've addressed this, however. The 87A
>control software worked flawlessly.
>
>From an operational perspective, I actually enjoyed using the 87A over the
>ACOM. High speed CW with a high power PIN diode is tough
>to beat, but then its less forgiving to high VSWR than the ACOM's Kilovac
>KC-1 vacuum relay. The ACOM was plenty fast and on my
>monitor scope, it never hot switched and the in/out sequencing was fine
>even at 45+ WPM.
>
>It's a close call., but I thought the overall construction of the 87A was
>superior to that of the ACOM. In one particular
>area....the motor servos, the ACOM uses a really scary Russian type. If
>you look at the servo, I swear it was machined by hand in a
>vise in someone's basement....very, very rough. However, they seemed to
>perform fine. Nevertheless, the look of the Russian servos
>scared the Hell out of me in the event the part no longer remained
>available or ACOM no longer supported the amp. On the other
>hand, if it's a common servo configuration both mechanically and
>electrical....maybe it's not a concern.
>
>In both ACOMs, I lost the 3-state electronic bias switch. Same part....a
>TO-220 switching transistor as I recall. Even though the
>amps did not come with a schematic (early 1999), I was able to repair it
>myself based on a couple e-mail exchanges with Vasko. I
>didn't detect any other problems in the two years I had the ACOMs. The
>only problem I had with one 87A was that the input
>bandswitch was not completely aligned and keyed properly. As the amp
>would automatically switch from band-to-band input VSWR would
>sometimes indicate considerably higher, but the fix was easy enough.
>
>The ACOM uses tubes that are less expensive than in the 87A. The 87A is a
>GG design. The ACOM uses tetrodes and the measured IMD
>performance of the 87A is significantly better than the ACOM 2000A
>(caveat: this data was measured by the ARRL labs on one set of
>amps. Another set of amps may have yielded different IMD figures).
>
>The ACOM's autotuning feature works differently than Alpha's. You find
>the optimum tuning and loading point within any band segment
>just once and forget it. If the antenna loading changes, the ACOM WILL
>NOT compensate. The 87A's ALPHAMAX will compensate for load
>changes, but it does not have a precise, one-time auto tune/load function.
> Yes, it is capable of full autotune, but it's not as
>precise as the ACOM. The 87A is best adjusted manually for a given band
>segment and then saved in memory. Then, I would engage
>ALPHAMAX to take care of the rest. The bottom line is that if you have
>antennas that are subject to loading variances, the 87A does
>the tuning best. If you can count on the antenna's VSWR to remain
>absolutely constant, the ACOM does a better job.
>
>Just my opinion....and worth just what you paid for it...
>
>-Paul, W9AC
>
>----- Original Message -----
>From: "Bob Otto N8NGA" <N8NGA@one.net>
>To: <amps@contesting.com>
>Sent: Wednesday, October 16, 2002 10:38 AM
>Subject: [Amps] Alpha 87A amp
>
>
>Forgive me if this is a subject covered......I'm new to the list.
>
>I'm considering purchasing a Alpha 87A amp 1Q03. The price has increased
>substantially since the new ownership. Does anyone have
>experience with the amp under the new ownership? Are there better
>alternatives to the Alpha?
>
>
>73 from....
>Bob Otto
>,,,,,,,
>Ô¿Ô¬
>Cincinnati, Ohio
>Scottsdale, Arizona
>«::::»¤«::::»¤¤«::::»¤«::::»
>Wednesday
>10/16/2002
>10:35:05 AM
>
>|¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥0¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥|
>"Direct to you from high on top of Indian Hill, Ohio"
>* DXCC 10M * * WAC 10M * * WAS 10M *
>N8NGA@one.net
>|¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥0¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥¥|
>
>If a lot of people gripped a knife and fork the way they do a golf club,
>they'd starve to death.
>
>~Sam Snead
>
>
>
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