[Hammarlund] HX-500 trials

Tue Apr 26 21:38:11 EDT 2016

     There is something strange about this. The ratios of correct to 
measured voltages vary. Of course, if the voltages are wrong the 
currents will be wrong too which may account for it.  I found a handbook 
and schematic at Rigpix. The instruction book states the voltages are to 
be measured with a 20K ohm/V meter so I don't think using the wrong sort 
of meter will account for it. However, if you do have another meter or 
can borrow one it would be worth checking just to make sure the meter 
itself is reading correctly.
    It would be interesting to know what your line voltage is. If you 
said I missed it.
    The difference in DC resistance of the chokes is probably normal 
tolerance. Also note the HV choke is a swinging one intended to provide 
some regulation to the supply.
    I can't find voltages listed for the transformer.


On 4/26/2016 5:59 PM, Jeff wrote:
> AC voltages out of the transformer are 900 VAC, 350 vac, 6.8 vac.
>
> Filter chokes test OK -- although I don't have my LCR bridge. 
> According to the schematics, the HV choke should have a resistance of 
> 160 ohms, mine is 172.  LV choke should be 250 ohms, mine is 271.
>
> LV circuit is a CLC filter.  At the output of the LV rectifier, 
> voltage is 380 vdc, should be 270.
>
> At the output of the CLC, voltage is around 280 vdc, should be 230.
>
> Regulated voltage is 151 vdc.
>
> Screen voltage is about 250, should be 200.
>
> Capacitors are what is specified in the Hammarlund power supply update 
> schematic.  My HV is running close to 1 KV.
>
> Voltages are just way high across the board.  I've gone over and over 
> the supply and verified nothing's shorted or connected incorrectly.
>
> The factory specification for the transformer was 
> 900-320-110-0-320-900, with filament lines of 12.6 and 6.3.  It was 
> run very close to the max voltage of the 6146, and hammarlund even 
> says to be careful switching the rig on and off.
>
> As always, appreciate the advice.  Still getting a solid 100 watts out 
> now of carrier, but can't test any further than that.
>
> Jeff
> WB3JIH
>
>
>
>
> On 4/25/2016 10:18 PM, Kenneth G. Gordon wrote:
>> On 25 Apr 2016 at 19:56, D C _Mac_ Macdonald wrote:
>>
>>> Maybe somebody converted a choke input power supply filter to 
>>> capacitor input?
>> That is a possibility:
>>
>> If the DC voltage out of the rectifier stack was around 640 VDC, 
>> going cap-input would give
>> around 900 VDC out of the filter (640 X 1.414 = 905), but choke input 
>> would show around
>> 575 VDC (640 X 0.9 = 576)
>>
>> Or, if the choke was shorted, the filter would then actually be a 
>> capacitor-only filter. With
>> ~640 VDC out of the rectifier, the output voltage would be around 905 
>> VDC as for a
>> cap-input filter.
>>
>> Seems to me that we have two problems here. Too high voltages, and an 
>> "issue" at the
>> final.
>>
>> Without killing himself, he could competely disconnect any and all 
>> filtering, then measure
>> the voltage out of the rectifier. That would tell us something...
>>
>> What is the AC voltage out of the transformer? That would also tell 
>> us something...
>>
>> Ken W7EKB
>>
>>
>> ______________________________________________________________
>> Hammarlund mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/hammarlund
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Hammarlund at mailman.qth.net
>>
>> List Administrator: Duane Fischer, W8DBF
>> ** For Assistance: dfischer at usol.com **
>>
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>
> ______________________________________________________________
> Hammarlund mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hammarlund
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Hammarlund at mailman.qth.net
>
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: dfischer at usol.com **
>
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL