Continuing the great Top Band dinner tradition that George, K8GG and George,
W8UVZ started, I am proud to announce the 25th Annual Dayton TopBand dinner.
Dinner reservations and Tickets are now available.
Friday evening May 16, 2014 at the Crowne Plaza in the Presidential Ballroom
- downtown Dayto
True! - Remember the warm glow of 866 rectifiers? Ever had one
"flash-over" from plate to filament? I did once, when, I think in the "heat
of battle" I applied the HV too quickly without enough filament and mercury
warm-up time! Used 'em as rectifiers in a home brew 805 gg amp. First real
amp I e
I have studied quite a bit of the history of polar exploration and I don't
think there is any correlation between solar activity and the launching of
polar expeditions. Multiple expeditions were undertaken to discover the
Northwest Passage, the North Pole, and then the South Pole throughout the
18
Yeah, those old "Benton Harbor Kilowatts" did a pretty good job on AM - not
quite as good as a Viking II or a Viking Ranger, but pretty good. Those old
1625 modulators and a real high-level plate-modulation transformer did a
pretty good job. When you consider what we had to pay for one, it enabled
Well, I agree. And if I follow your reasoning, it doesn't take much of an
increase in line voltage to push the HV from 825 VDC to over 900 VDC., as
Bill observe. Might be the choke, but I'd be really surprised at the
entire
winding being shorted. I'd surely want to start by measuring line voltag
Somewhere around here I have info about adding those 'funny wires' and
neutralizing the rig. It was already on my table to do that. I don't
plan to use the DX-100 shorter than the 80 meter CW band but want to get
to the point I can just switch it on, warm it up, and go. I'm looking at
other mod
So far I haven't found the line voltage lower than 125 Volts and in early
afternoon it was at 130 volts. The transmitter was working and no problem
with the finals at all before I did the recap. I did the power supply
recap in all three power supplies because the low voltage supply was
getting
- Original Message -
From: "Bruce"
To:
Sent: Wednesday, January 08, 2014 5:43 PM
Subject: Topband: Chasing Shaclelton
Why did so many polar expeditions take place in periods of high solar
activity ?
Did they believe that sun spots would result in higher earth polar
temperatures?
-Original Message-
From: Charlie Cunningham
( Maybe I spent too many
years around electric utilities) I think that +/- 5% guideline is honored
more in the breach than in the observance. In the meter business "480
high-line" was 530 VAC!
73,
Charlie.K4OTV
On 01/08/2014 05:33 PM, Keith Jillings (G3OIT) wrote:
In my (very distant) youth I came by a DX-100 that had been built from
kit by a local, who could never get it to work. I spent a few
interesting weekends studying the circuit and the construction, and
then set to with a hot soldering iron
On 01/08/2014 05:19 PM, Charlie Cunningham wrote:
Well, here in Raleigh, I've seen it go a good bit more than 5% high at
night. Still, I wonder if Bill could just put some higher voltage
electrolytics in there, tune for "maximum smoke" and "let 'er rip" - and
count on the key-down sag to keep the
Why did so many polar expeditions take place in periods of high solar activity ?
Did they believe that sun spots would result in higher earth polar temperatures?
They found quite the reverse was true.
Chasing Shackelton premieres today (tonight in NA) on PBS-TV. Check your local
listings for t
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 h
Well, here in Raleigh, I've seen it go a good bit more than 5% high at
night. Still, I wonder if Bill could just put some higher voltage
electrolytics in there, tune for "maximum smoke" and "let 'er rip" - and
count on the key-down sag to keep the 6146s safe? ( Maybe I spent too many
years around e
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.
Line voltages in the late 1950's were 115, and 117 at the time the DX100 was
made. The standard since the 70's is
Hi, Bruce
Well, I agree. And if I follow your reasoning, it doesn't take much of an
increase in line voltage to push the HV from 825 VDC to over 900 VDC., as
Bill observe. Might be the choke, but I'd be really surprised at the entire
winding being shorted. I'd surely want to start by measuring li
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 shor
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, i
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 gr
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 pas
I had used four caps rated at 450 volts/100 uF. They were in two pairs
series parallel for 100 uF/900 volts. Some hams cautioned me against using
so much capacitance. So I removed one pair of the caps and ended with 50
uF at 900 volts. The plate supply remained over 950 Volts until I keyed
the
So..
Here is where I am with the DX-100. I have been operating it with a pair
of 2E26s where the 6146s live and feeding those from the low voltage
supply. When I completed the recapping of the high voltage power supply
the finals immediately started giving me trouble. So I disabled the high
v
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