AMECO AC-1 issues
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weaselradio1@...
I have an AMECO AC-1 that I bought 35 years ago and I am just now trying to see if it can be used. Unfortunately, I let the magic smoke out of the power transformer tonight. I really hate to give up on a toy, but does anyone know what the secondary windings output voltages might be and more to the point, where one of these puppies can be procured. I'm betting its toast, and I need to start looking for an alternative transmitter. Any help out there?
Bob KE0FAT |
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John Lonigro
Bob:
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If you do a Google search on Ameco AC-1 schematic, you'll find a schematic someone posted. On it, he mentions the secondary is 200-300 volts center tapped at 50-100 ma. On a different schematic, I saw the filter capacitor is rated at 450 volts, so you know the filtered DC must be less than that, probably quite a bit less. Hope this helps. Out of curiosity, how were you able to blow the transformer? You'd think the fuse would have blown first. 72, John AA0VE On 07/14/2015 11:44 PM,
weaselradio1@... [4sqrp] wrote:
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weaselradio1@...
A fuse would have been a smart move. I replaced the rotten original power cord, but had neglected to add a fuse . Pretty dumb for a safety engineer. I'm not certain where the circuit fault is, but the transformer sacrificed itself to protect the cheaper downstream parts.
Thanks for this information, I will start looking into obtaining the components. Bob KE0FAT |
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davemrtn
I am guessing the transformer did not sacrifice itself. It is more
probable it was put to death by a downstream component.
Before you replace the transformer, you should thoroughly test the rectifier and filter capacitor. My first suspicion would be the capacitor. On 7/15/2015 6:25 AM,
weaselradio1@... [4sqrp] wrote:
-- David Martin - K5DCM Mountain Home, Ar. -+-+-+-+-+-+-+-+-+-+- "It's only "work" if you'd rather be doing something else" - Dean Kamen SCOTUS has legalized perversion, and heathens are celebrating. |
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There is a Yahoo group, of which I am a member, that is dedicated to
the AC-1 and the cult like following of this rig.
You will find all the information that you need and more to find a replacement transformer and all manner of things you never knew about the AC-1 . I HIGHLY suggest that you become a member. The AC-1 was the first kit, as a Novice in 1965, that I was able to buy for around $16. That was a LOT of lawns to mow in those days:) Loved the little rig but it got away from me and I have never been able to afford to replace it. I had upgraded my license and rig when a new Novice, "borrowed" it and it never returned. Best 73, Charlie, W5COV On 7/15/2015 6:25 AM,
weaselradio1@... [4sqrp] wrote:
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Don Wilhelm <w3fpr@...>
With a transformer that old, it is quite possible that it did
sacrifice itself, but it is difficult to say.
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I would do a recap job on that AC-1 before attempting to apply power, particularly the electrolytics since they have likely dried up - in those times, many capacitors were paper wrapped and do not age well. 73, Don W3FPR On 7/15/2015 10:17 AM, David Martin
davemrtn@... [4sqrp] wrote:
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John Lonigro
And I would put a fuse somewhere in the circuit, probably a
slo-blow due to the high inductance of the transformer. You might
consider putting one in the secondary circuit as well. Fuses are
cheap.
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72, John AA0VE On 07/15/2015 10:40 AM, Don Wilhelm
w3fpr@... [4sqrp] wrote:
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weaselradio1@...
There are a lot of good comments here. Yes, I believe I was a little too anxious to get this working to fully check out the components before applying power. Lesson learned.
Dave, your right! There is a failed component downstream of the transformer and I'm sure the transformer was an induced failure due to this problem. I noticed one of the tubes was had arcing inside the tube instead of the normal glow and the other tube didn't seem to have any power (no glow). I believe there was smoke coming from the electrolytic capacitor after I pulled power as well as the transformer. It looks like I will get to spend some quality time with the whole transmitter before I apply power again. Bob KE0FAT |
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davemrtn
Sorry about the circumstances, but have fun digging into it and
making all new again. You will be all the more proud of it when
done. Take your time and do forget the TLC.
I do hope you can find all the parts you need, and they are reasonably priced. These days, if available, tubes just seem to cost way too much, but then they aren't being manufactured in the quantities they were years ago.... On 7/15/2015 12:23 PM,
weaselradio1@... [4sqrp] wrote:
-- David Martin - K5DCM Mountain Home, Ar. -+-+-+-+-+-+-+-+-+-+- "It's only "work" if you'd rather be doing something else" - Dean Kamen SCOTUS has legalized perversion, and heathens are celebrating. |
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davemrtn
DARN, that was supposed to be "DON'T forget the TLC". poor proof
reading on my part before clicking send.
On 7/15/2015 12:31 PM, David Martin
davemrtn@... [4sqrp] wrote:
-- David Martin - K5DCM Mountain Home, Ar. -+-+-+-+-+-+-+-+-+-+- "It's only "work" if you'd rather be doing something else" - Dean Kamen SCOTUS has legalized perversion, and heathens are celebrating. |
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weaselradio1@...
Not a problem. I blame most of my typos on my tablet's auto-correct feature
 . I did a little checking and the rectifier was the tube that was arcing (little lightning like sparks between conductors internal to the tube) and the 6V6-GT never got warm. I think I will start working with the power supply tonight and see how long it takes to get to the rest of the circuit. |
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sigcom1
Sorry to hear about the PT in your AC-1. The problem might have been caused by a shorted 6X5 rectifier. Although I've never experienced it with any AC-1, the 6X5 has a bad reputation among the antique radio enthusiasts with shorting and taking out the power trans. (un-fused primary).
The AC-1 PT spec's are as follows: Secondary voltages without load: 6.3 V filaments AC 300-0-300 V AC nominal. This generally varies from 290-0-290 to 325-0-325 depending upon line voltage. Dimensions: 3" wide x 2 1/2" deep x 1 3/4" high. Stamped with "T-141" or "T-141 H" on the end bell. This info is from the "AC-1 FAQ" document on the AC-1 Yahoo Group. <https://groups.yahoo.com/neo/groups/amecoac1/info> The above voltages are from measurements. To the best of my knowledge, voltage and current spec's. for the T-141 have never been published. 40 mA on the HV secondary would be adequate and whatever the combined currents for the tube heaters is. Best of luck with the project and 73.......Steve Smith WB6TNL AC-1 Yahoo Group Moderator ____________________________________________________________ Old School Yearbook Pics View Class Yearbooks Online Free. Search by School & Year. Look Now! http://thirdpartyoffers.juno.com/TGL3141/55a6a259ace8922595e6cst02vuc |
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weaselradio1@...
Well, rumors of my transformers death were exaggerated. It turns out the smoke was real, but the death had not occurred before I shut down. At the suggestion of the electronic shop owner I buy my parts from, I verified my output voltages from the power transformer.
So, today I replaced the electrolytic capacitor and found two new tubes (well new to me) replaced them on the radio. I still need to add the fuse. But it does work and I am getting close to 10 Watts. As soon as I get back up to speed with my Morse code I hope to get on the air. Thank you all for your suggestions. Bob KE0FAT |
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davemrtn
HOORAY !!! Have Fun.
On 7/15/2015 8:52 PM,
weaselradio1@... [4sqrp] wrote:
-- David Martin - K5DCM Mountain Home, Ar. -+-+-+-+-+-+-+-+-+-+- "It's only "work" if you'd rather be doing something else" - Dean Kamen SCOTUS has legalized perversion, and heathens are celebrating. |
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