Ken, it's outstanding that you have resolved your difficulties with your 8410. I know the folks at Alpha take pride in their workmanship and sometimes they need to be humbled by something bad happening to one of their products. I believe you got a lemon, one made on Monday morning before first coffee or one made late afternoon on Friday when the coffee wore off.
If this replacement amplifier fails after 3 weeks let us know but odds are you're going to be a happy camper from now on.
That is great to hear. Outstanding service for sure.
They actually sent me a brand-new amplifier last week. So far, the new amp works great!!
Maybe the first amp just had some "growing pains."
Let's hope your second amp will be more stable.
I would imagine Alpha is going over the first amp with a fine toothed comb.
73 and good luck!
There are two types of oil filled capacitors: Those intended for continuous filter service and those intended for intermittent photo-flash service. The latter type has thinner foil and for a given rating is smaller than the type for filter service. The thinner the foil the higher the ESR and the higher the I2xR loss when ripple current is present. However, a flash service C can be used in filter service if it is derated to 60% of working V. Operating an intermittent flash service C at it's full V rating in filter service results in heating that eventually can cause failure of the seals. . . . In ordinary intermittent amateur radio use one might be able to get by with a flash rated C - but for contesting, probably not.
Originally Posted by VK6ZGO
At one time Peter W. Dahl was selling surplus oil-filled caps. After purchasing 2 for a FWD I was building, I found out about the two types of oil filled caps - so I became suspicious and ran a ripple current test on them. They got hot -- confirming that they were flash caps. Peter refunded my $$. .
You are right about not taking things for granted.
It is my opinion that it is not good engineering practice to use a flash-rated C in filter service.
This is really good information Rich!
Originally Posted by AG6K
You say that "ALPHA is a top-notch company with super service". REALLY!! Well, I went to Dayton, Ohio this May and went directly to the ALPHA Stand at the Hara Arena because Molly Hardman, the so-called Vice-President of ALPHA Sales, sent me an e-mail and invited me to "drop by" when I was in Dayton. I stood by Ms. Hardman for more than 90 minutes while she utterly ignored me and talked to everyone around her but never talked to me. My call sign was displayed very prominently on my hat and I know she recognized who I was. After being sent a total lemon that died on me after only three weeks of use and now after being totally ignored by Molly Hardman when I attempted to talk to her at Dayton, I give this firm and their employees a total ZERO in customer relations!! By the way, the second ALPHA 8410 that they shipped to me has been running perfectly for almost four weeks.
Originally Posted by NU1O
NO, the topic of this thread is how someone who spent $5,300 for an ALPHA Amplifier was sent a total lemon that self-destructed in only three weeks.
Originally Posted by KB4QAA
No, I didn't solve my "difficulties" with ALPHA. ALPHA solved all my problems by shipping me a brand-new 8410 Amp. The first one they shipped me was a LEMON. The one I have now is working just great. Unfortunately, the folks at ALPHA tried their best to place the blame on me for all the problems I had with the first amplifier. The technician's report was absolutely incredulous. First they tried to say that I was using a 115 volt AC plug on my 8410. Then they said that the 240-Volt wall outlet was really a 115-Volt wall outlet. Then they said that I probably caused all the failures by inputting more than 40 Watts into the ALPHA. They also suggested that my antennas caused all the problems. Then they wanted to know if I had tried to tune up using a dummy load instead of an antenna. Etc., etc., etc. They never once admitted that the amplifier I had was a LEMON.[/B]
Originally Posted by KO6WB
It is standard operating procedure - SOP - for human orgs to deny and blame others for their mistakes. The original Corvair automobile had a rollover problem that took years, a number of expensive injury lawsuits, and publication of an embarrassing book before GM would fix their design error. A friend was injured in a Corvair rollover.
Originally Posted by W3XAF
Another example of denial is a large religious org that initially tried to blame child victims for a centuries-old mistake that was of the org's own doing. 900 years ago when the mistake was made a man named Pete Comestor warned of the danger but nobody in the org payed any attention. Eventually this mistake cost the org $3,000,000,000 in out of court settlements and serious loss of street cred. . . . . Congrats to Pete C.
Yet another example of denial is TL-922 bandswitch arcing across open contacts. For years Kenwood techs said it was due to TL-922 owners rapidly switching the bandswitch while transmitting at full power. How could any mfg be so clueless as to imagine that any Ham radio operator is really this stupid? . . . The cause of the arcing turned out to be the 0.3pF of feedback-C in the 3-500Zs. At the frequency of the TL-922's anode parasitic resonance c. 120MHz, 0.3pF has about 5000Ωs of reactance. Since 3-500Zs have been successfully used to build 144MHz push-pull amplifiers, is it any mystery that they can oscillate at 120MHz with a 5000Ω feedback path between the anode-output and the cathode-input? Duhhhhhh.
There is no tube that does not have feedback-C --- yet some HF/MF amplifier engineers ignore this potential source of grief and do not take adequate measures to reduce VHF amplification to discourage parasitic VHF oscillation -- or incorporate glitch-protection to limit damage in case a parasitic oscillation ever pays a visitation. .