Will a Texas Star 350HDV operate 10-80 meters???
Barry
Can anyone familiar with the older style Texas Star High Drive 350 with the variable power knob tell me if
it will
work 10-80 meters in a mobile installation, or is it designed strickly for 10/11 meters? If need be,
is the modification to cover the entire hf spectrum posted anywhere? I'm running an Icom 706 and a BB3
screwdriver type
antenna. - Thanks in advance / Barry Vermont
--
Barry
"tw·,..," wrote:
> X-No-Archive: yes
>
> "Barry" <lumin...@madriver.com> wrote in message news:3C7E4057...@madriver.com...
> People answered you already in your old post below. BTW, it is illegal to use a RF amp on 11 meters.
--
No body has answered my question yet, and who said anything about using it on 11 meters?
graywolf
It looks like c10 and c32 on the schematic is used to limit its
frequency response. So to get the amp to run 10-80 you may have to
change the values of these caps. If you zoom in on the parts table
they give a range of values. Since the amp uses broadband transformers
to match the transistors to 50 ohms. The amp will work 10-80.
http://www.texasstar.com/350HDVschematic.gif
Are you planning on using the amp with the 706? If so, you are not
going to gain much. This amp using two 2sc2879's. The transistors are
rated at 100 watts pep each. You are only going to gain 3dB and
probably less over the 706.
GW
Barry <lumin...@madriver.com> wrote in message news:<3C7E4057...@madriver.com>...
Train
Train
"graywolf" <graywo...@yahoo.com> wrote in message
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Bad Apple
confusion lies.
"Train" <cbm...@optonlineNOSPAM.com> wrote in message
news:UWxf8.13160$Iu2.4...@news02.optonline.net...
Barry
Now to fiqure out the correct values of the replacement capacitors.
Only 3 db gain when doubling the power output? - I'll take it.
graywolf wrote:
--
graywolf
and IMD is -24 dBc. Looking at the PO Vs PI graph 100 watts PEP looks
to be about the 1dB compression point (P1dB). To go beyond that the
transistor is being driven into the non-linearity range.
"Train" <cbm...@optonlineNOSPAM.com> wrote in message news:<UWxf8.13160$Iu2.4...@news02.optonline.net>...
Richard McCollum
> Thanks Much GW and Train for your input and the link to the schematic.
> Now to fiqure out the correct values of the replacement capacitors.
> Only 3 db gain when doubling the power output? - I'll take it.
>
With all due respect Barry, you are in way over your head.
1. Broadband does not mean DC to light in any case. The cores of the
matching transformers must respond to the freqs in question, stray
capacitances and inductances figure into the formula. Without knowing
what they did, it is absolutely impossible to to say with any accuracy
what it would do with or without the capacitors. Coming out of CB it is
fair to say it was cheap, half-assed or both.
A transformer has to store a complete cycle so one doing it on 3MHz is a
bit larger than one doing it at 30 MHz. Again, the odds of their
transformer being equal to the task is slim and none. Even American 60 Hz
transformers and motors get a bit warm on the European 50 Hz and you don't
even want to know what a 25 Hz xfmr looks like. There was a reason WW2
aircraft used 400 Hz AC, Weight, man, Weight. What do you think the odds
might be that these guys used one big enough?
While a screwdriver will resonate admirably, just what its input impedence
may be is known only but to God without a lot of work. What makes you
think a transformer designed for the ragged edge on 27 MHz and a 50 ohm
load will do on 14 with a 20 ohm load. If you said puke you win one
silver dollar.
2. You seemed to express some surprise that doubling power is 3 decibels
which tends to make me believe you have no concept of logrithmic
relationships. If you can't get 10 dead birds you are playing with
yourself. Even the AM broadcast rules are set up at 50k, 5k, and .5kw
because if you can't get 10db it isn't worth the effort. The diff between
300 and 100 watts will be significant maybe twice a year if you are really
active.
3. You are plunging into this like a rookie CBer firmly convinced CB is
radio; it is not. Rather it is a restricted band and garbage freqs at
that so that things are skewed into a real hothouse environment and a real
gang of thieves. Couple that with enough mythology to fill several Cecil
B. deMille movies and the net result is that when you know CB, you really
don't know shit. Some, like Jay and others, know bullshit when it is
presented -- the mark of an educated man. Not entirely convinced that you
do, or even want to. That is sad. Self-education is the name of the
Amateur game and you are blundering about like Ahab looking for a whale.
Said another way, ignorance is curable but stupidity is for life.
4. The same blind 'CB is radio' BS will cause you to ignore other aspects
of self-ed including such wonderment as operating practices and
recognizing what band condx are and how to deal with them. You will miss
out on the comraderie for no better reason than any reasonable soul will
look at this installation you will show off with great pride and remember
he had an appointment in Pawtucket Gulch an hour ago. Take the blinders
off Toto, this ain't Kansas any more.
5. Your first lesson. Technicianing.
a. know when to quit
b. know when never to get started
c. you can't out-engineer the man who built it armed with twofanzines
and a parts catalog.
Dick NØBK
--Jeff Mayner--
"tw·,..," <.tw,@nothomeexcite5,yahoomsnATTBI.org.com> wrote in message
news:40zf8.352$sx.10873@sccrnsc02...
> X-No-Archive: yesnews:3C7EA8FA...@madriver.com...
> > No body has answered my question yet, and who said anything about using
it on 11 meters?
>
>
meters/11 meters.
Re-read the post again, or, better yet, have it read to you by someone that
has better comprehension skills. Geez, you were so hot to throw your
unwanted and unasked for opinion out there you didn't take even a moment to
read the entire post. You've made a complete and utter fool of yourself.
Jeff
>
>
>
Richard McCollum
"--Jeff Mayner--" <bk...@pacbell.net> wrote in message
news:3LFf8.46390$7a1.3...@bin5.nnrp.aus1.giganews.com...
Made a fool, Jeff? You cannot kill the dead. :-)
--Jeff Mayner--
> X-No-Archive: yes
>
> "--Jeff Mayner--" <bk...@pacbell.net> wrote in message
news:3LFf8.46390$7a1.3...@bin5.nnrp.aus1.giganews.com...
that
> > has better comprehension skills. Geez, you were so hot to throw your
> > unwanted and unasked for opinion out there you didn't take even a moment
to
> > read the entire post. You've made a complete and utter fool of yourself.
>
>
Moron? MORON??
How DARE you?
Jeff
>
>
>
--Jeff Mayner--
"Richard McCollum" <rmcco...@worldnet.att.net> wrote in message
news:QPIf8.7626$106.4...@bgtnsc05-news.ops.worldnet.att.net...
QSL :-)
Jeff
>
>
>
Train
Just kidding...........The more power the better I like it!
Train
"tw·,..," <.tw,@nothomeexcite5,yahoomsnATTBI.org.com> wrote in message
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> X-No-Archive: yes
>
> "Barry" <lumin...@madriver.com> wrote in message
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Jerry Oxendine
Barry
This particular amp (old style)was produced before Texas Star got clever with the xtal controled cw transmitter
design working around the fcc rules.
I do not have the original schematic for it, but I doubt that it's changed much in theory.
Can an air variable capacitor take the place of the fixed caps to make it see 50 ohms at any given frequency
between10-80 meters?
With those ratings, the two 2sc2879's aren't going to produce nearly the stated output of 350 watts at 13.8
volts. Oh Well, It was worth asking. Tnx / Barry
Richard,
Forgive me for being logrithmically challenged, but how much power must I run to get that
only worth while 10db gain, up from 100 watts?
Keep it down to a novel, if you can.
Just trying to learn something here . Thats all.
PS- individuals with RF Brain Damage need not apply.
Resume fighting now.
Richard McCollum
>
> Richard,
> Forgive me for being logrithmically challenged, but how much power must
I run to get that
> only worth while 10db gain, up from 100 watts?
> Keep it down to a novel, if you can.
> Just trying to learn something here . Thats all.
Decibel, named for good old Alexander Graham Bell, deci is tenths.
The idea in audio is that one dead bird is the smallest unit where a
difference can be determined by the human ear and that the perception of
loudness is not linear. So ninety dbA is perceived as twice as loud as 80
dbA when in fact it has 10 times the mechanical moxie behind it. The
Richter scale is logrithmic, a six is ten times a five. It happens rf
does this as well. It is a method of comparison so it is often used, as I
just did, as a comparison to a standard so you will see dbm (comparison to
a milliwatt across 600 ohms traditionally, 50 in a lot of cases), dbi vs a
so-called isotropic radiator, a dbA is with respect to a minimum
perceptable sound,etc. The range of sound from perception to pain BTW is
about a factor of a trillion or 120 dbA; the range of rf runs from about
.25 microvolts per meter for audibility to where the standards set in at
about 80 volts per meter (WHO standard).
Back when broadcast audio was done over phone lines, Ma Bell liked things
at 0 dbm which did not imply no signal, just a milliwatt over their
nominal 600 ohm phone lines so zero-level, now known as 'line level', was
marked on all the station boards and you see the needles bouncing into the
red in all the old movies.
So to double your signal, you need ten times the power or 10 db or 1 bell.
If you can't go to a kw, forget it in other words.
The nice thing about dead birds is that one can simply add and subtract
them for a lot of things so if you pick up 12 db in a full max amp, and 8
in an antenna you have 20 which is a ratio of 10**2 or 100 and most
certainly worth the effort if you can stand the expense for which you
basically get four times the perceived moxie. So to a large extent, the
pride of ownership is second only to the expense.
The formula is db = ((10 (log P1/log P2)) but it is easier to simply
remember that 10 db is a factor of 10 and a doubling is 3db. So if you
double power you get 3db, double again and you are up to six, double again
and get nine and the last dead bird gets you the full factor of ten.
Won't win you the accuracy trophy but in the inexact world of radio it
works well enough.
Kind of makes you think when you see a -55 db output from a mike and that
is a fairly hi output one; some magnetic carts were -80 or so. Also tends
to give you an idea why driving by a church on Sunday morning with the
services being recorded and you on your Belchfire 500 amp showed up in the
services better than the preacher.
I hope by now you might have figured out why going from 100 to 300 (if you
can get that hi) is right up there with pissing in the wind, you at least
are pissing downwind, and why the experienced souls here kind of asked
just why you would do that. The installation would be an object of
wonderment and worship but not what you might expect.
A lot of junk is sold to people who seriously believe that tripling one's
power triples range. Some with a bit of geometry are willing to settle
for the square root, 1.763 but not too many would buy it if they realized
how little effect it really has.
**************
I know I did and fully intended to flame your pretty pink tushy in the
spirit of the man beating his mule with a 2x4 trying to get its attention.
To be honest, I did not expect much if any response. I am happy to be
wrong.
Dick NØBK
--Jeff Mayner--
> > Moron? MORON??
> >
> > How DARE you?
> >
> > Jeff
>
Heh...
Double!
Jeff
>
>
>
Dennis W. Ostrowski
> Decibel, named for good old Alexander Graham Bell, deci is tenths.
> The idea in audio is that one dead bird is the smallest unit where a
> difference can be determined by the human ear and that the perception of
> loudness is not linear.
-snipped out for brevity-
> The nice thing about dead birds is that one can simply add and subtract
> them for a lot of things so if you pick up 12 db in a full max amp, and 8
> in an antenna you have 20 which is a ratio of 10**2 or 100 and most
> certainly worth the effort if you can stand the expense for which you
> basically get four times the perceived moxie. So to a large extent, the
> pride of ownership is second only to the expense.
>
-Snipped out for brevity-
> I know I did and fully intended to flame your pretty pink tushy in the
> spirit of the man beating his mule with a 2x4 trying to get its attention.
> To be honest, I did not expect much if any response. I am happy to be
> wrong.
>
> Dick NØBK
Dick,
A few comments (in the same spirit as this 'educational' thread):
1) The Texas Star amp was one of the very few amplifiers that were originally
designed with bias, so they were a little better than the rest that were out
there at the time.
2) The Texas Star 350 High Drive is not really a high drive and his 100 watt
driver will burn out the swamping resistors in the front end in short order,
putting a quick end to any power gain debates.
3) I know people who are using the Texas Star DX500 amplifiers on 10 thru 80
with no problems.
They work better without any tuning at all than the old Metrons did with all
their switchable impedance matching networks.
4) In your scenario in the prior post where you halved the frequency (27MHZ to
14MHZ), you also halved the load requirement (50 OHMS to 20 OHMS), so the
transformer should work admirably. If you halve the reflected impedance you
only need one half the minimum required inductance for the transformer to work
properly,(as long as your collector current does not saturate the core); and the
ferrite mix they used does not saturate easily. The core materials for such
applications are usually selected to have the highest CURIE temperature and not
necessarily the highest AL value because you don't need that much inductance at
27MHZ to make an efficient broadband transformer. The other thing that works
to help broadband the unit is the fact that the transistor gains increase
dramatically as the frequency decreases.
5) Your dead bird explanation was a good one, but instead of just plinking them
off the fence one at a time, my daddy taught me to wait at one end of the fence
and when they land on the fence a single well placed shot will get them all! A
10 to 20 DB gain every time!
Regards,
Dennis O.
Richard McCollum
"Dennis W. Ostrowski" <dwost...@lucent.com> wrote in message
news:3C8007F0...@lucent.com...
Richard McCollum wrote:
-snipped out for brevity-
-Snipped out for brevity-
Dick,
I have actually heard a few and they did more or less run. They were
popular with some of the 10-watt Japanese rigs before that laid an egg but
a couple of TV transformers and a 4CX250 scrounged from commercial service
was my cup of tea for that dubious purpose. I think the key here is
'originally'. Things got mighty cheap later.
2) The Texas Star 350 High Drive is not really a high drive and his 100
watt
driver will burn out the swamping resistors in the front end in short
order,
putting a quick end to any power gain debates.
To his credit, I think Barry is well aware of this.
3) I know people who are using the Texas Star DX500 amplifiers on 10 thru
80
with no problems.
They work better without any tuning at all than the old Metrons did with
all
their switchable impedance matching networks.
I would expect they are being run into tuners or something that does not
impose quite the burden on them. I will admit to having a VHF bias
against untuned amps that grew out of Micors which were among the great
broadband mixers of all time. With some form of antenna isolation, OK,
but the concept disturbs me in the hands of the public.
4) In your scenario in the prior post where you halved the frequency
(27MHZ to
14MHZ), you also halved the load requirement (50 OHMS to 20 OHMS), so the
transformer should work admirably. If you halve the reflected impedance
you
only need one half the minimum required inductance for the transformer to
work
properly,(as long as your collector current does not saturate the core);
and the
ferrite mix they used does not saturate easily. The core materials for
such
applications are usually selected to have the highest CURIE temperature
and not
necessarily the highest AL value because you don't need that much
inductance at
27MHZ to make an efficient broadband transformer. The other thing that
works
to help broadband the unit is the fact that the transistor gains increase
dramatically as the frequency decreases.
If one could be assured they used a large enough core of something that
could be traced OK. I am assuming powdered iron and that comes in
frequency ranges so a priori one would have to guess whether they used a
20-50 MHz mix or a 3-30 mix.
Points well taken, thank you for the education.
5) Your dead bird explanation was a good one, but instead of just plinking
them
off the fence one at a time, my daddy taught me to wait at one end of the
fence
and when they land on the fence a single well placed shot will get them
all! A
10 to 20 DB gain every time!
Yup, blasting them with the 12-gauge is damned hard on fences. In my
tootling around Omaha I have noted that on a 71kv transmission line Star
the crows perch on the ground wire only, never the hot wires. So while
waiting for my load of kids, I contemplate whether it is because it is on
top or if they do not enjoy being part of the near field :-)
Regards,
Dennis O.
Barry
I understand now, how the multiplier works .
The 350HDV's the wrong tool for the task.
Glad I asked first.
You're not as pompous as I originally suspected.
Tnx Again / 73-Barry
Aaron H. Voobner
news:3C8007F0...@lucent.com...
>A few comments (in the same spirit as this 'educational' thread):
>
>1) The Texas Star amp was one of the very few amplifiers that were
>originally designed with bias
Agh. Now you've gone and done it, Dick. By mentioning Texas Star, you
brought one of those slimy "CB amp techs" crawling out of the
woodwork. Soon this Dennis character and his pals will be waxing
poetic about keydowns and illegal Xforce CB amps....
-A
Richard McCollum
> I appreciate the meaty explanation Richard, infact I may need a doggy
bag.
> I understand now, how the multiplier works .
> The 350HDV's the wrong tool for the task.
> Glad I asked first.
> You're not as pompous as I originally suspected.
> Tnx Again / 73-Barry
>
I suspect you and I have both met the guy who once you convince him he is
the smartest man in the room you can steal his shorts and sox without
removing shoes or pants. Made a bit of money that way.
I have covered a few miles but there ain't any big Red S on my sweatshirt.
graywolf
After reading your reply to Richard. You made a good decision. The
350HDV, is the wrong tool for task.
I'm assuming that you are operating mobile, I would recommend one of
the solid state amplifiers, manufactured by a more reputable company.
Ameritron makes the ALS 500. It produces 500 watts pep that's will
give 7 dB of gain. Another company is Henry radio they produce several
solid state amplifiers. The 13.8 volt SS500 and SS750. Ten Tec use to
produce a mobile amp too. Though I don't see it on there webpage.
These amps are not cheap but you might be able pick one up on the used
market.
GW
Barry <lumin...@madriver.com> wrote in message news:<3C801085...@madriver.com>...