Randy or Sherry Guttery wrote:

Ok so I mixed db and dbi, point for you. Now tell me that 1000W is
"almost" indistinguishable at the recieving end from 10W - and S-units
are a valid comparison standard...

Well this time my spell checker got me - try again - mixed dB and dBu,

(field strength). that's what i get for shooting fast and from the hip...
--
randy guttery

A Tender Tale - a page dedicated to those Ships and Crews
so vital to the United States Silent Service:
http://tendertale.com

Randy or Sherry Guttery wrote:
vt245 wrote:
What??? 10W - 1000W is 20db. Distance doubles every 6db - do the math...

6db is for voltage and current NOT for power .... do the research

Ok so I mixed db and dbi, point for you. Now tell me that 1000W is
"almost" indistinguishable at the recieving end from 10W - and S-units
are a valid comparison standard...

I won't tell you that they are almost indistinguishable. But I will say
that S-units should be a valid comparison standard, at least with military
gear that _is_ calibrated in 6 dB increments.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"Lazy Senior" wrote in message
newsse9f.3726$zT6.3512@trnddc06...
I recently acquired a Viking Ranger in nice working condx.

I am interested in using this on AM on 160, 80, and 40 mtrs. The Ranger
runs around 40 watts Am carrier output. I would like to get an amplifier
to use with this xmtr, maybe a vintage amp. What should I be looking
for? I would like to run legal Am Limit on these 3 bands. Should I
forget about Vintage Amps and get a modern Amp? Suggestions please. Any
pitfalls to using a modern Amp?

Thanx

Lazy Senior

This is not as easy as it seems. AM peak power is
4 times the carrier. A 100% modulated 40 watt AM
signal is actually producing 160 watts PEP.
The linear amplifier could only be driven to about
25% output on an unmodulated carrier from an AM transmitter,
otherwise it would be severely overdriven on modulation peaks.
If you could drive a linear to 1000 watts, the maximum carrier
power for AM would require the drive to be set for about 250
watts max.

If you want more power you could drive a class C amplifier, and
apply high level modulation directly to it. Trying to "amplify" an
AM signal is very, very inefficient and difficult to set up properly.

Pete

Uncle Peter wrote:


This is not as easy as it seems. AM peak power is
4 times the carrier. A 100% modulated 40 watt AM
signal is actually producing 160 watts PEP.

Yes, I know it is not as easy as it seems, that is what I posted the
message looking for suggestions.

I presently use a Viking Valiant putting out 140 Am carrier watts. It
has worked very nicely.

Now also,I have a Viking Ranger, puts out 40 Am carrier watts. I want
more power, especially on 160 mtrs.

Ok it is 1956 when these xmtrs were made. If I had a Ranger then, what
would I buy for an amp?

I realize one problem I may have is 160 mtrs (a band I love) was
restricted in 1956 and many radios, xmtrs, amps didnt have 160 mtrs.

So, I want to run 375 watts Am Legal limit with a Viking Ranger on
160,80,40 mtrs preferably with a Vintage Amp, but will consider modern amps.

What are my options - no homebrew..

thanx

Lazy Senior

"Lazy Senior" wrote in message
news:ysf9f.20182$ti.12230@trnddc02...
Uncle Peter wrote:

Ok it is 1956 when these xmtrs were made. If I had a Ranger then, what
would I buy for an amp?


Heathkit KL-1 Chippewa? Although that probably dates a few
years later, and may have been a "match" for the Apache.
The 4-400s could probably withstand the
duty cycle for AM operation. Besides the PEP issues, you have to
make sure the amp and its power supply will withstand AM
continuous carrier operation.

Most hams back then would have used the Ranger as an exciter
for a Class C amplifier deck with it's own high-level AM modulator.
That's the best way to do what you propose.

On Sun, 30 Oct 2005 21:46:05 -0500, " Uncle Peter"
wrote:


Most hams back then would have used the Ranger as an exciter
for a Class C amplifier deck with it's own high-level AM modulator.
That's the best way to do what you propose.

100% correct.

Lazy Senior wrote:
Uncle Peter wrote:
Ok it is 1956 when these xmtrs were made. If I had a Ranger then, what
would I buy for an amp?


Johnson desk kilowatt, lots of them get driven by Rangers.

Ron

Johnson desk kilowatt, lots of them get driven by Rangers.

Ron

To buy an EFJ Desk Kilowatt you need to be prepared to
mortgage your house, wife, and kids or win the lottery...

If you are only satisfied with the VERY best, then follow this link. This
particular rig only runs 500 watts on 160, but that's because that was the
legal 160 meter limit when the transmitter was sold. I am sure it would be
easy to remove the artificial power constraint for 160 meters. Go for it!
http://www.wa3key.com/kw1.html

"Lazy Senior" wrote in message
newsse9f.3726$zT6.3512@trnddc06...
I recently acquired a Viking Ranger in nice working condx.

I am interested in using this on AM on 160, 80, and 40 mtrs. The Ranger
runs around 40 watts Am carrier output. I would like to get an amplifier
to use with this xmtr, maybe a vintage amp. What should I be looking for?
I would like to run legal Am Limit on these 3 bands. Should I forget about
Vintage Amps and get a modern Amp? Suggestions please. Any pitfalls to
using a modern Amp?

Thanx

Lazy Senior

Hi,

No real pitfall with a modern amp, as long as you get one
rated for continuous duty a.m. operation.
You need tubes with a lot of plate dissipation rating,
since a.m. linear is inefficent, maybe 25% carrier efficiency.
Look for a linear with ceramic tubes, a big blower
and a heavy-duty power supply.

You may need an rf power attenuator between the Ranger
and the linear. Most modern linear amps
produce 1500W peak output with only about 65w peak drive.
Your Ranger will produce 160W pep output in a.m. mode
(at 40W carrier). The linear will be producing 375W carrier,
at legal limit, so it will be almost 10dB more output
than the barefoot Ranger. With no modulation,
the linear's power input will be about 1,500 Watts
(assuming 25% efficiency).
A lot of heat will be dissipted from the linear's plates,
about 1,125 Watts.

A T-network made of 3 each 100W lightbulbs may be an OK
rf attenuator at the linear's input, so you don't overdrive it.

73,
Ed Knobloch






Lazy Senior wrote:
I recently acquired a Viking Ranger in nice working condx.

I am interested in using this on AM on 160, 80, and 40 mtrs. The Ranger
runs around 40 watts Am carrier output. I would like to get an amplifier
to use with this xmtr, maybe a vintage amp. What should I be looking
for? I would like to run legal Am Limit on these 3 bands. Should I
forget about Vintage Amps and get a modern Amp? Suggestions please. Any
pitfalls to using a modern Amp?

Thanx

Lazy Senior