I'll bet the fuse that appeared visually intact was 1A not 1.5A.
Larry
WB6BBB
On Tue, 8 Nov 2022 17:05:47 -0500, David Tenenbaum <dmt013@gmail.com> wrote:
>I think you have nailed it Chris: I had initially visually checked the slow
>blow fuses and they looked fine, but an ohmmeter confirms one is not
>conductive. My bad for not checking it with a meter first time around.
>Embarrassing!
>
>Two followups:
>
>1) The schematic says 1.5 amp slow blow, but the chassis stencil says 1.0 amp
>SB. I am guessing it should not matter too much which I go with?
>
>2) Should I be looking at an underlying root cause before trying it with new
>fuse? I guess worse that can happen is it blows again....
>
>Thanks for the help, sorry for the rookie oversight!
>
>David
>N1RO
>
>
>
>
>> On Nov 8, 2022, at 4:52 PM, c miller <c_miller_1@hotmail.com> wrote:
>>
>> Not too odd really. On 120v it is possible to run the initial startup cycle
>> on just one of the two windings. Then once the soft start circuit bypasses
>> then both windings come into operation and unit preforms as intended.
>> However, with either fuse F3 or F4, or resistor R6 or R7, in the soft start
>> circuit being open, no power ever gets passed on to the transformer thus
>> locking the rig in a power off state. The relay k11 (click) is the only
>> part that is able to operate in that failure mode
>>
>> Chris
>> VE3CEA
>>
>>
>> Sent from my iPhone
>>
>>> On Nov 8, 2022, at 16:31, gudguyham--- via Amps <amps@contesting.com> wrote:
>>>
>>> ?It?s odd that it works on 120 and not 240. I looked in the manual but the
>>> terminal strip is not numbered on the schematic.
>>>
>>>
>>> Sent from the all new AOL app for iOS
>>>
>>>
>>> On Tuesday, November 8, 2022, 3:24 PM, David Tenenbaum <dmt013@gmail.com>
>>> wrote:
>>>
>>> Thanks for the feedback!
>>> I am still on the clock at work but took a break to check R8 and I am
>>> seeing 3.98K ohms, so the 4k resistor seems intact. Later tonight when
>>> finally done with work I will tear into it to look at the fuses and other
>>> resistors, confirm there is REALLY 220 v getting to the unit, and anything
>>> else that comes up.
>>> Thanks all for the ideas!!!!
>>> David N1RO/VE3TMK
>>>
>>>
>>> On Nov 8, 2022, at 2:33 PM, gudguyham@aol.com wrote:
>>> Did you check R8 for open?
>>>
>>>
>>> Sent from the all new AOL app for iOS
>>>
>>>
>>> On Tuesday, November 8, 2022, 2:20 PM, David Tenenbaum <dmt013@gmail.com>
>>> wrote:
>>>
>>> Hi All,
>>>
>>> I have an Alpha 86 that I have been using set up for 110v, and finally have
>>> access to 220v, so looking forward to seeing what it can REALLY put out.
>>> Unfortunately I have made the jumper changes (terminal in the back for 110
>>> operation has locations 1&2 jumpered, 3&4 jumpered, and 5&6 jumpered, but
>>> for 220 only locations 2&3 are jumpered), and the unit fails to light up or
>>> come online. I hear a single relay activation when I hit the "On" switch,
>>> but no lights or fan.
>>>
>>> Fearing I hurt the unit I restored it to 110v operation and all is good. I
>>> set it back to 220v and same problem. I checked continuity from the plug's
>>> ground to chassis ground, and the hot leads show continuity to the right
>>> places. I have been using a 220v SB200 on that outlet just fine.
>>>
>>> Any thoughts or leads appreciated! Never thought I would have a problem
>>> just switching supply voltages.....Scan of schematic attached....
>>>
>>> Best,
>>>
>>> David
>>> N1RO/VE3TMK
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