yep.. saw a 4-1000 at a hamfest, looked well used, the guy wanted $135 for it, when I asked for a guarantee that it was
reasonably good, he lowered the price to $50, so I suspected.. and passed. "sure it's good, hilk hilk.. nope, not mine, belongs
to a buddy, hilk hilk.." No way to test something
That's at -26dB, to allow the usual 6KHz without bizzarre filtering. I think it is to sugest a curve of a filter which would be
easy to implement.
>>And, just for the sake of me knowing, why would you (or ANY AM'er for that
>>matter want to have audio that was 9kc wide?
Ok, I'll ramble on about it. I have a few vague points.
The cited article seems to be mostly about digital bandwidths and
segregating the subbands by bandwidth rather than emission type.
It does mention an AM bandwidth limitation of -26dB@ 9 KHz. (I
wonder how many 6SN7's it would take to buil
> It is only necessary to reduce filament voltage by a few tenths of a volt,
> which is not going to hurt anything. The first thing you should do is check
and
> monitor your power line voltage. Mine varies during the day by +5 volts! A
> variac is the easiest way to control it but you have to b
This link might be helpful for this discussion:
http://www.cpii.com/eimac/index.html
Care and Feeding of Power Grid Tubes by Eimac.
It is only necessary to reduce filament voltage by a few tenths of a volt,
which is not going to hurt anything. The first thing you should do is check
and
monitor your power line voltage. Mine varies during the day by +5 volts! A
variac is the easiest way to control it but you have to be able
> The theory that I have seen holds that the cathode of a tube is
> protected against ion bombardment by the electrons it emits. When
> the emission capability of the tube is not exceeded, the cathode
> tries to emit too many electrons, but they have nowhere to go, so
> they cluster around the c
> Too low of a filament voltage WOULD be detrimental to the tube life, BUT
> reduced PLATE voltage while maintaining full filament voltage WILL
> extend the tube's overall lifespan.
>
> That's an area that I agree with Don completely!
>
> It's the one place that variac use on start up of an ol
> >Of course, we know that running voltages that are too high will kill the
> >life expectancy of the tube, by why is running too little voltage bad for the
> >tube, if it's developing full emmission at a lower voltage?
>
> I think low voltage would be ok as long as you are not exceeding the curren
The theory that I have seen holds that the cathode of a tube is
protected against ion bombardment by the electrons it emits. When
the emission capability of the tube is not exceeded, the cathode
tries to emit too many electrons, but they have nowhere to go, so
they cluster around the cathode and b
Don, is this same fest that used to cover a few acres at the campus
location?
Thank you again for these reports.
Dave, W3ST
Publisher of the Collins Journal
Secretary to the Collins Radio Association
www.collinsra.com
Nets: 3805 Khz, Monday/Wednesdays 8 PM EDST
14250 Khz Saturday, 12 N
Too low of a filament voltage WOULD be detrimental to the tube life, BUT
reduced PLATE voltage while maintaining full filament voltage WILL
extend the tube's overall lifespan.
That's an area that I agree with Don completely!
It's the one place that variac use on start up of an older stored rig
A while back, you said something about running too little voltage on the
older
big jugs, like 833's, 250THs, 4-1000's, etc...
Of course, we know that running voltages that are too high will kill the
life
expectancy of the tube, by why is running too little voltage bad for the
tube,
if it's d
I attended the Warren ARA hamfest in Warren Ohio yesterday. It was about an
hour and 45 minutes drive for me--longer than I would have liked, but easy to
find. Fest management was excellent and the breakfast food was good. They had
space for probably 200 vendors and about 35 showed up. Many of
Calling K4KYV, Don, from W5OMR.
Many wise and sage advices have been given out by your station in the past, Don,
including one I use still, this very day;
"Running your AM Rig without a 'scope, is like driving your car at night without
headlights" (-Don/K4KYV AM/PX)
A while back, you said somethi
FS: Misc BA Gear
Military WWII TS-34/AP ocilloscope. These WWII-era tst
oscilloscopes with their distinctive shape and rubber
viewing hood used to be common in surplus. But like
the command sets, now they are somewhat harder to
find. This one is in nice original shape and has the
rubber hood. $39
I see that the 9 kc bandwidth is at -26 db (not dbm in which 0 db is
set at 1 mw). -26 is way down there. Normally bandwidth is measured at -6
db, the half way point. Since the sides slope, what is the bandwidth at
-6 db? It could easily be 6 kc or so.
73, Ed Richards K6UUZ
On Mon, 16 Aug 200
Since we are talking AM I think the audio would have to be 4.5 kc wide to
produce an AM signal at 9kc -26dBm.
73
Mark N5RFX
At 10:02 PM 8/15/2004, you wrote:
And, just for the sake of me knowing, why would you (or ANY AM'er for that
matter want to have audio that was 9kc wide?
Traditionally AMers have been opposed to any bandwidth enumeration. Look
at the history of docket 20777. I just am wondering if this is still the
case? I hope not.
73,
Mark N5RFX
And, just for the sake of me knowing, why would you (or ANY AM'er for that
matter want to have audio that was
Don is right
I remember well the first attempt of 'bandwidth' limits on the bands...
We need to watch this close... very close
73
Vince
ka1iic
-.--.
On Monday 16 August 2004 04:25 am, Donald Chester wrote:
> One problem I see is that the FCC has a habit of twisting rulemaking
> requests
One problem I see is that the FCC has a habit of twisting rulemaking
requests to fit its own agenda as the actual rules are formulated, and
sometimes the end result has little resemblence to the original proposal.
Those who were around in the mid 70's will recall a similar plan was
proposed
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