Years ago in a land far-far away all video coax connectors in Broadcast
Television were UHF (PL259).
We only tightened them hand (finger) tight. In may places pliers would have
not fit any way.
In black & white days we would want to be flat from DC to around 8 MHz with
a smooth roll off to
Paula Keezer NX1P modified a KPA500 to allow it to be driven to about 500
watts by a KX3.
She published it - but I can not find it on the web.
The mod increased the gain by less than 3 db (seems I recall 2.something).
You would need the 12 to 15 watts to drive it to about 500 watts.
The
Works from Windows Live Mail
73
George AI4VZ
-Original Message-
From: Brian Denley
Test
Brian KB1VBF
Sent from Mail for Windows 10
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Help:
It was on the 2nd phone as well!
Not sure if it was one I had to draw or just identify.
My recollection is that the 2nd phone was much much harder than the present
Extra.
My commercial licenses were 1959. My Ham license is 2007.
73
George AI4VZ
-Original Message-
From: Fred Jensen
A couple of solutions used in TV Broadcasting, especially in ENG & Satellite
mobile units.
1) Use a short jumper from the large conductor the the connector. I solder
the 2 wires together (inline) and cover the connection with shrink tubing.
This helps when you want flexibility between the large
I have 24xx K3. It did need the mod. Actually put in when I had a LP
pan-adapter before the P3.
The mod is changing one resistor. R8 from 1k to 13k. I used a 1/4 watt only
because I do not stock 1/8 watt.
On the Elecraft web site K3IOBUFFKT - IF Output Buffer Gain Modification is
the kit for
Andreas,
You might want to go to the station and talk the the Chief Engineer. If he
is the nice-guygal type CE he will help you (Not al CEs are the nice kind
but most are).
I'd suggest that he/she cycle the two transmitters on/off while you are at
your station. He/She won't do that during the
Jack,
Don't use a 15 pin straight through - not all pins are to be connected. My
recollection is that 1 or 2 pins Must Not be connected to the K3!
Use the manual if not using the Elecraft Aux cable sets.
Because not all VGA cables are the same - you can use a VGA cable if you
positively confirm
-Original Message-
From: Jack Brindle via Elecraft
...
Now having said this, the ATU can also be bypassed in the K3, and that circuit
may provide a proper 50 ohm source/load for the BPF. I would probably take this
approach myself (and in fact do so in my station). The reason I take
Astron has an Over-Voltage protection option that is an add-on accessory.
In the past it was an option or included on some models.
If the regulation series transistor shorts or the regulation circuits
malfunctions, then the over-voltage protection shorts the output and blows
the fuse(s).
My
Richard,
My KXAT3 goes down many unpaved gravel roads in the mountains of North
Georgia and has for many years - since June 2012.
At times we joke that the roads are actually potholes inter-connected by
short stretches of gravel pavement.
The KX3 lives in the cab of a Ranger pick-up mounted on a
Bill,
We used the "slip-ons" to have quick reconfiguration of monitors on a live
remote (TV) truck when we were still using UHF connectors for video.
We had no failures that I remember - remote live trucks live in a very
hostile environment!
We used the UHF slip-ons until the conversion to BNCs
One other thought to keep in mind - solid state amps need a lower delta T
than tube amps. Tubes like to run hot - solid state devices not so much.
I've seen a tube with the fins so hot that the solder was in globs, while
the transmitter was still operating. I doubt any solid state final would
Ken & Rich,
As a broadcaster, we used hundreds even thousands of BNC video cables - they
are no more finicky then another RF coax cable until you get to hard line or
Helix (which are bullet proof in N, UHF or EIA).
Unless the cable has an improperly installed connector or the cable is
damaged,
Rich,
Even massive grounding systems do not keep a tower from being hit! It only
mitigates the damage.
I was CE of a TV station in South Florida with towers of 1,000' a couple at
500' and several more at 100' to 200'. They all got hit at one time or
other. Sometimes many times a year.
We used
A differing view:
Having benefited greatly by the Telecommunications Act of 1996 in my former
professional life, I doubt that the HOA, POA or COA (X owners associations)
have been asleep at the wheel in dealing with antenna issues since then!
Senator Nelsen's defeat of this bill last year for
Christopher,
Many of us who have upgraded have extra old style synthesizers with no plans
for them.
If the cost of upgrading your main synthesizer is stopping you from getting
a sub-receiver, I and many others would be glad to loan or give you an old
style one.
In the long run a sub-receive
Bill,
Try using a sharp soldering aid to "tighten" the female connector contact on
the K3 & P3.
Pry the female center contacts inward just a bit.
73
George
AI4VZ
-Original Message-
From: Bill Breeden
Sent: Friday, April 7, 2017 1:18 PM
To: Jim LeFevre
Cc: elecraft@mailman.qth.net
Ed & Brian,
My father had severe health consequences from working in a classroom with
operating military radars!
Since the adoption of OET 65 in the late 90s, all licensees (including Hams)
have had the responsibility to insure their station is in complete
compliance with RF exposure limit
Her website.
Her copywrited paper is also available at:
http://www.oz6hq.dk/userfiles/downloads/kpa500%20mods.pdf
Shows details about her modification to add 2.5 db gain by eliminating the
input attenuator and modifying the sensor circuit to keep the protection
circuit - protecting.
Elecraft
I agree Dan,
Make a modification kit available to licensed operators and blessed by
Elecraft.
Kit of parts w/pc board would be ok by me.
Maybe one with 2 inputs - one for K3 (100 watt rigs) and another for KX2 or
KX3 (QRP) rigs.
Seems wasteful to feed the KPA500 with a KX3 + KPX100 to the input
Noel,
This subject is well discussed on this reflector from time to time.
I suggest starting with the discussion on Don's (W3FPR) web site -
http://www.w3fpr.com/.
Go to the "Noisy K3? - Adjust your AGC Settings" section. That paper has a
very good explanations of the K3 AGC system operation.
Bill,
I use a KX3 with the KXPA mounted on the lid of the cargo box in the pick-up
bed. Antenna is mounted on the other side of the lid.
The "separation" cable works perfectly.
My KX3 is mounded to a pole from the passenger seat bolt just above the
center consol. I find this location ok, but do
Joe,
A vote for neither! Actually to be fair to others - a vote to keep them as a
low priority.
But:
Would love to see TX-Mon on SVGA - but also low priority. I have rearranged
my shack to have P3 back in front of me.
Also would like TX-MON to have audio spectrum display as a selectable
option.
Maybe Elecraft can weigh-in about the "Burn-In Time" for the boards used in
the kits.
I have all kits and suspect that my Elecrafts are actually as good as
factory except they were assembled by a rank amateur (Elecraftwise).
I do know that I had no qualms about modify the filters or motherboard
AMEN Lynn!
Download the Elecraft Utility for the KX3, KXP3 and KXPA100 if you haven't
yet.
They are located at
http://www.elecraft.com/software/elecraft_software_page.htm
The back-up configuration is in the Utility for each.
When you have time roam about in the Elecraft web site. You will need
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