Topband: DX-100 adventure contiunued

["Bruce" <k1fz@myfairpoint.net>]

Hi Charlie,

A little cross multiplication shows that if you had 600 volts when the 
primary is 110 VAC,   then with 130 primary volts you should have 709 Volts.
A larger increase takes place between choke input and  capacitor input. 
(depends upon the size of the capacitor)   Most likely a shorted choke or a 
miswiring problem. (Was the transmitter a kit?)
Best to check the choke resistance.
Does both ends of the choke have the same resistance back to the rectifier 
filament connection ?  You should see the choke resistance as a difference.
73
Bruce-K1FZ





----- Original Message ----- 
From: "Charlie Cunningham" <charlie-cunningham@nc.rr.com>
To: "'Bill Cromwell'" <wrcromwell@gmail.com>
Cc: "'topband'" <topband@contesting.com>; "'Tom W8JI'" <w8ji@w8ji.com>
Sent: Wednesday, January 08, 2014 3:14 PM
Subject: Re: Topband: DX-100 adventure contiunued


> Hi, Bill
>
> Well, I suspect that the light bulbs may be a "tip-off". The do make 130
> volt bulbs for folks with line voltage that runs a bit high, but that
> doesn't help you DX-100 or other appliances. Sounds like you need to get
> you power provider to look into  you line voltage and regulation. Also, if
> they have power-factor correction capacitors connected on those 
> distribution
> feeders in the winter-time when the power factor is less inductive and
> closer to unity, that can result in soe increase in line voltage in the
> winter time. GL!
>
> 73,
> Charlie, K4OTV
>
>
> -----Original Message-----
> From: Bill Cromwell [mailto:wrcromwell@gmail.com]
> Sent: Wednesday, January 08, 2014 2:45 PM
> To: Charlie Cunningham
> Cc: 'Tom W8JI'; 'topband'
> Subject: Re: Topband: DX-100 adventure contiunued
>
> On 01/08/2014 01:36 PM, Charlie Cunningham wrote:
> > Hi, Bill
> >
> > I was also going to ask if you have a choke input filter -or if you could
> > change the PS filter configuration to choke input to help a bit with the
> HV.
> > Also, check your line voltage - especially at night when the load on the
> > electric grid drops. I've seen my 240 VAC  here get up well past 265 
> > volts
> > at night! Use a trusted, well calibrated volt meter and take some voltage
> > readings at different  times of day to get a feel for what the line
> > regulation looks like!  Note that a 10 % increase in line voltage would
> > increase that HV from 825  VDC to over 900 VDC.  10 % high line is not
> > really unusual.  Finally, you can check with your local PUC - there are
> > regulatory limits to how much the AC line is permitted to vary - but I'd
> > start with the power provider first. Maybe they need to drop your
> > distribution feeder down a tap at the substation. Excessive voltage is
> hard
> > on lots of things around your house besides DX-100s! The utility can cme
> out
> > and put a recording voltmeter on your line for a while to see what's 
> > going
> > on, if you complain about excessive line voltage.
> >
> > GL!
> > 73,
> > Charlie, K4OTV
> Hi Charlie,
>
> The DX-100 High voltage is choke input by design. I changed the low
> voltage supply to choke input as well and the rf stages are behaving
> very nicely with that. I already think my line is "high" and I'll take
> readings various times as you have suggested. Light bulbs don't seem to
> last very long here, either.
>
> Tom asked about bleeder current. I didn't try to measure it but I
> watched the high voltage decay to zero in a very few seconds when I
> switched it off with no 6146s in the sockets.
>
> 73,
>
> Bill  KU8H
>
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