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  #21   Report Post  
Old January 16th 08, 01:01 PM posted to rec.radio.shortwave
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Default RHF = Idiocy & Brain Damage



m II wrote:

D Peter Maus wrote:

YES BUT,
He is very ugly, has hair hanging out his nose and ears, his
eye brows are grow together and he has two chins.

Burr



So, he's Canadian?



Grow up.


Well, we wish you dumbass Canucks would!


  #22   Report Post  
Old January 16th 08, 06:20 PM posted to rec.radio.shortwave
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Default RHF = Idiocy & Brain Damage

bpnjensen ) writes:
On Jan 16, 2:31=A0am, BCBlazysusan wrote:
On Jan 15, 10:50=A0pm, RHF wrote:





On Jan 15, 6:50=A0pm, wrote:


On Jan 15, 12:56 pm, wrote: Poor Roy, he must h=

ave been exposed to massive amounts of microwave
energy or RF energy. He simply cannot make a post without those
redundant cut n' paste links he deems important to life on this
planet.


What a goddamn dork!!!


+++++++++++++++++++++++


-=A0Keep in mind the guy was a government bureaucrat for 30 years.


Bureaucrat -nah- I was simply a low level US Civil Servant doing a
Job.


-ps- It was 32+ Years


- That explains why he acts the way he does.


Could Be . . .


- The arrogance and compulsive {with a} need to be in charge


Very True.


- (evidenced here by his self appointed moderator role) and


Clearly I am failing at that task : Based on this and other Posts
about me; and not about Shortwave Radio.


- his smug "I'm the smartest guy in the room" attitude.


Dang - You Got That Right -but- Then Again I do sign many of
my Posts "pomkia" - POMKIA =3D Plain Old Mister Know It All .


- In short, he's a caricature of himself - pompous, arrogant, self
- righteous, hypocritical


http://www.octanecreative.com/knowitall/jpgs/mr_kia.jpg


- (chronically scolding others for off topic posting while he is
- one of the worst offenders) and obnoxious


Dang - You Got That Right !


- the consummate {petty} bureaucrat.


Again - I was just a low level US Civil Servant.


- =A0Roy's 30 years as a government parasite


The Truth {Reality} is that the vast majority of US Civile Servants
are Good Decent Hard Working People who Earn their Salary.


- making the lives of people who paid his salary miserable
- prepared him well for his current role as
- resident pain in the ass.


Well at least I appear to have succeeded with you. ) ! ~ RHF
=A0.


RHF,
Don't let em' get you down. FWIW I have your back. I really need to
start posting posting more. I really miss Steve/Bryants
'conversations'....lol.....those were classics IMO back in the day.
Many great people IMO in here just a few bad apples. Ole' DXlover
waving a hand at you. :-)- Hide quoted text -

- Show quoted text -


Ditto too, and RHF, you're OK in my book - I may not always agree with
your politics (but sometimes do), but there is no shame at all in your
postings about radios, antennas and equipment, or how to use them.
The feebs who have criticized? I doubt if they know a kilowatt from a
kilocycle.

Some bozo who constantly yammers on, posting when he usually has little
to say, posting links rather than real comments, posting in a completely
unreadable style, constantly changing subject headers, playing
"moderator" when his skill is so horrific that it only makes things
worse, and being a big source of the animosity here, well that defines
the state of the newsgroup. "RHF" isn't the only one, but he certainly
enables the other junk posters.

Wade through the off topic posts, the political bickering and admonishments,
and there isn't much here. Far better for the yammerers to be silent for
a time than to constantly spew. And yes, you will see three or four
posters, including the bozo "RHF", in the thick of all that drivel.

There was a time when if someone asked a simple question, they'd be
told to look it up themselves. But nowadays, this newsgroup is full
of people who do that work for the lazy, merely posting links. And
when people do that, who's to know whether they know anything or not?
There is no value in posting such links, because the original poster
should be doing that work themselves. But instead, we get all these
link posters, and nobody around to really address the question that
may not be properly asked.

The only reason this bozo RHF is getting accolades is because
the newsgroup has decayed so much that many have left, and a new
wave that doesn't know better has moved in. SOmeone who can't keep
his mouth shut is bound to dominate a newsgroup, and that's what people
are reacting to. Look between the lines, and there is little of substance
there, and the only reason he becomes a "valuable source" is because the
good posters of the old days have faded away, so there's nothing better
than a bozo posting links.

A newsgroup is not healthy if only a handful dominate. Drive off a wide
range of readers, and the newsgroup declines, because as long as people
are reading a newsgroup, they may reply when they actually have something
to add, so some obscure topic gets a real answer instead of another
stupid link. Or that person who only replies a few times a year may
have some obscure bit of knowledge that few know, so if they tune out,
there goes the knowledge.

It's telling that the bozo RHF never looks things up in this newsgroup,
he's constantly linking to other sources of information.

This is what the newsgroup used to be like, before the bozos and the village
idiots took over:

From: (Michael Black)
Subject: Double conversion Vs Triple conversion
Date: 2000/02/17
Message-ID:
X-Deja-AN: 587020050
References:
Organization: Communications Accessibles Montreal, Quebec Canada
Newsgroups: rec.radio.shortwave

In article , dan wrote:

All:
I am considering buying a new World Band reciever;
(- this may be my lifes work )
Does anyone know, in laymans terms, what the advantages of a triple
conversion receiver Vs double conversion receiver are;
and, if one is listening Just to world band, is there a really good
choice of triple conversion receiver;
all things (antenna, location) being equal..
Really difficult to hear stations are the most interesting to try to
receive; Indonesia,
New Zealand on a bad night, WBCQ on Saturdays.. etc.
- Dan


How many conversions a receiver has is not a direct indication of
performance.

The whole point of superheterodyne receivers is to get the incoming
signal to a frequency where amplification and selectivity can
easily be accomplished.

The superhet is something like 80 years old, which is barely younger
than radio itself. When it was invented, the state of the technology
could only mean that the superhet would convert to a lower frequency.
It was easier to get amplification there, and since it was a fixed
frequency as opposed to variabl4e frequency if amplification took
place on the signal frequency, you wouldn't need constant readjustment.
Selectivity may have been a mere byproduct; I know I've seen early
schematics of superhets where provides no selectivity, only amplification.
Of course, with time, selectivity became an important reason for
the superhet.

But once the superhet was invented, it became clear that there was
a problem. In the conversion to another frequency, the IF (Intermediate
Freuqency), you'd also get an image frequency. Basically, that
meant that anywhere you tuned the receiver, you would pick up two
signals, the one you want and one that was a side effect of the conversion.

With the relatively low frequencies used for the IFs in the early days,
the only way to get rid of the unwanted image frequency was to put
more selectivity on the signal frequency, which in some ways
the superhet was supposed to eliminate. Usually there was no
problem in the AM broadcast band, and even in the low shortwave
bands, because relatively simple front end selectivity could give
enough rejection of the image frequency. But a lot of cheap
receivers from the old days bombed on the highest band, the one
that ended at 30Mhz, because there was way too little selectivity
in the front end to get rid of the image frequency.

Of course, the more expensive receivers did put more selectivity
in the front end, and suffered far less. The HRO series were
manufacturered up into the sixties (or was it the late fifties?),
and they still had a 455KHz IF. But they had two RF stages and
associated tuned circuits to get rid of the image frequency.

With time, somebody thought of the idea of double conversion. Convert
the incoming signal to a frequency high enough that it would place
the image frequency far enough away that the front end would reject
it sufficiently, and then a second conversion to a frequency
where the real amplification and selectivity could take place. Of
course, if the design wasn't done right, it could be horrible since
you now had two sets of image frequencies to get rid of, and of course
you added a second oscillator inside the receiver to generate
spurious signals.

Triple conversion was just an extension of that, though in some cases
it was used to add special features.

One of the problems of double, or triple, conversion is that in
that era it put a fair amount of amplification before the ultimate
selectivity of the receiver. So the tuned circuits before the
final IF would take out the image frequency, but a strong signal not
that far from the desired signal would pass without attenuation,
and if it was strong enough it could overload one of the stages.

With time, technology allowed for a different implementation of
the superhet. You could have good selectivity at a high frequency,
and of course tubes and later transistors got good enough that
they could amplify with no problem at high frequencies.

So there was a move back to single conversion receivers, with
the IF in the 9MHz range, or thereabouts. The IF was far
enough away that only the strongest signals on the image frequency
could get by relatively simple front end selectivity. And the
selectivity could be put right after the mixer, meaning that all
the rest of the receiver saw only the bandwidth of a single "channel".
The mixer was still vulnerable to overload, though there were
improvements in that area around the same time, but at least it
was reduced to only one mixer. And in many cases the high IF
allowed for no amplification before the mixer, again helping
the receiver's overload resistance.

Of course, there were problems. Having the IF in the middle of
the range the receiver was trying to tune was a problem. And those
crystal filters could be expensive.

With time, mainly when ICs allowed for cheap synthesizers so the
local oscillator could operate at a high frequency and still be
stable, the first IF moved up above the 30MHz. The whole shortwave
band could then be tuned without a gap, and there were other
good reasons for moving the IF there.

The problem was that a filter at 45MHz or so could be terribly
expensive, and it might even be difficult to get narrow selectivity
in that range.

So receivers moved back to double conversion. The filter at the first
IF would be little wider than the widest selectivity desired, so
the rest of the receiver would have to deal with a relatively small
slice of spectrum. And the IF was high enough that virtually
anything in the way of front end selectivity would reject the image
frequency, allowing for quite a bit of flexibility in the front
end design. Of course, the overload resistance of the mixer
became an issue as the selectivity decreased in the front end; it
had always been a problem, but image rejection had been a more
immediate need for that front end selectivity.

And of course, triple conversion also returned. But it was for
things like passband tuning, rather than to deal with limited
technology.

The point to all this is that conversion is a trade-off. Triple conversion
will give you pass band tuning, but if not done carefully will give
you spurious responses. But that triple conversion is giving you
a feature, better to be assesed on the basis of that feature, rather
than as an absolute. If you wanted to pay the high price, a single
conversion receiver with a bank of filters of various bandwidths
operating at 45MHz or so would probably be best, since you don't
have to worry about the problems of multiple conversion. But
people want multiple bandwidths and lower cost, so you end up
with double conversion receivers. Likewise, they want poassband
tuning, so they end up with triple conversion.

But you can't compare two receivers by looking at how many conversions,
and say this one is better than that one because it has double (or triple
conversion). You have to look at the overall design, and the specs.

As for scanners, that someone brought up in this thread, the need
for multiple conversions is a reflection of the wide frequency;coverage
that many of them provide, and the multiple conversions could be
seen in the same light as multiple conversions in receivers of
yesteryears. They need it to get rid of the image frequencies.
The technology hasn't caught up enough with the needed range.

Michael

  #23   Report Post  
Old January 17th 08, 01:40 AM posted to rec.radio.shortwave
RHF RHF is offline
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Default RHF = Idiocy & Brain Damage

On Jan 16, 3:44*am, IBOCcrock wrote:
On Jan 16, 5:26*am, oneway wrote:





D Peter Maus wrote:
wrote:


On Jan 15, 4:07 pm, D Peter Maus


* *There's a lot of personality, here, too. Truth is, Roy has most of
it. But if Roy chooses to make a career out of participating in this
group....so what? If he's got the time and the resources....God Bless
him.


* *The question is....what does it matter to YOU?


+++++++++++++++++++++++++++++++++++++++++
*It matters because his compulsive posting of irrelevant bs has driven
away many shortwave enthusiasts who visit daily and contribute
regularly to the group. Most no longer bother to even read the group
much less post because they have long ago tired of the little clique
of posters who now dominate the group.


* It's like the friendly neighborhood bar that everyone that mattered
once enjoyed gathering that gets taken over by a few *obnoxious
drunks. The change in atmosphere is almost imperceptible because it
happens over time. One by one the regulars stop dropping in and *soon
the only patrons are the obnoxious loud mouthed few and the bar soon
goes bankrupt.


* So yes, it matters sir.


* Then you serious need to refocus your priorities. If you can be run
off by one poster's style...I'm guessing shortwave wouldn't be your best
choice of avocation.


The question for you Peter, is why do posters like Roy, Burr, Steve and
others get a pass from you when they are the source for most of the OT
garbage on this group? My guess is that you secretly support their
politics and world views but don't want to admitt it here. You didn't
use to be like that in the good old days. You made mostly useful
contributions and rarely responded to the OT posts. Now you almost
encourage them. What happened?
(Hint: 'nothing happened' is not an acceptable answer)- Hide quoted text -


- Show quoted text -


- Peter is another Goddamn rightous konow-it-all!

. . . and I B OC'Deed and Half Crocked - You Are A
"Know Nothing" Of The First Water ~ RHF
  #24   Report Post  
Old January 17th 08, 01:43 AM posted to rec.radio.shortwave
RHF RHF is offline
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Posts: 8,652
Default RHF = Idiocy & Brain Damage Day - TYVM For Making My Day ~ RHF

On Jan 16, 3:30*am, "Burr" wrote:
"RHF"

For One and All - I Want To Thank Everyone {TYVM} for making
15 January 2008 "My Day" {RHF} on this Newsgroup.

For all the other Idiots and Brain Damaged People : Who Shared
this Day with Me - thank you, Thank You. THANK YOU !

lets do it again next year ~ RHF
*.

Ya, Happy 15th. Many happy returns

Burr


Burr - "Happy {April} 15th. Many Happy Returns"
Did you ever do some work for the IRS ? ~ RHF
  #25   Report Post  
Old January 17th 08, 01:44 AM posted to rec.radio.shortwave
RHF RHF is offline
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Posts: 8,652
Default RHF = Idiocy & Brain Damage

On Jan 16, 3:39*am, IBOCcrock wrote:
On Jan 15, 5:07*pm, D Peter Maus wrote:





wrote:
On Jan 15, 12:56 pm, wrote:
Poor Roy, he must have been exposed to massive amounts of microwave
energy or RF energy. He simply cannot make a post without those
redundant cut n' paste links he deems important to life on this
planet.


What a goddamn dork!!!


That is all.


Everything he (RHF) posts is like that, he probably weighs 350 lbs.
and sits in front of his computer 24/7 buck ass naked. Those freaks
from Northern California are like that!


He obviously needs to get into town and get a life other than a
computer and shortwave radio.


I obviously own a computer and several shortwave receivers, but don't
make a career out of either.


Rev. Willie T-Bone Johnson


* *I find it amazing the number of people who stop by here and take
shots at those who participate at a high level.


* *Congratulations on being a member of the shortwave community. Which
receivers do you use? And which are your favorites?


* *Myself, I'm partial to AR-7030+ and Ten-Tec RX-350. With a side of
dozens of others ranging from Lowe HF150 to Hammarlund BC794 SuperPro.
DXAce over there to your right, in Michigan, is partial to Drakes, and
has quite an arsenal. Telamon to your left, in California, hits with
Ten-Tec RX-340. And you'll find assorted Grundigs, Hallicrafters,
Panasonics, and ICOMS, with the occasional National, and RCA thrown in.


* *There's a lot of personality, here, too. Truth is, Roy has most of
it. But if Roy chooses to make a career out of participating in this
group....so what? If he's got the time and the resources....God Bless him.


* *The question is....what does it matter to YOU?- Hide quoted text -


- Show quoted text -


"Congratulations on being a member of the shortwave community. Which
receivers do you use? And which are your favorites? "

I just got a cheapie $25 Kaito WRX911, and was reminded that there is
nothing of interest on SW, unless one enjoys religious fanatics.- Hide quoted text -

- Show quoted text -


PTL and Turn-Up the Volume ~ RHF


  #26   Report Post  
Old January 17th 08, 01:50 AM posted to rec.radio.shortwave
RHF RHF is offline
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First recorded activity by RadioBanter: Jun 2006
Posts: 8,652
Default RHF = Idiocy & Brain Damage

On Jan 16, 3:35*am, IBOCcrock wrote:
On Jan 15, 4:33*pm, wrote:





On Jan 15, 12:56 pm, wrote:


Poor Roy, he must have been exposed to massive amounts of microwave
energy or RF energy. He simply cannot make a post without those
redundant cut n' paste links he deems important to life on this
planet.


What a goddamn dork!!!


That is all.


Everything he (RHF) posts is like that, he probably weighs 350 lbs.
and sits in front of his computer 24/7 buck ass naked. Those freaks
from Northern California are like that!


He obviously needs to get into town and get a life other than a
computer and shortwave radio.


I obviously own a computer and several shortwave receivers, but don't
make a career out of either.


Rev. Willie T-Bone Johnson


"Everything he (RHF) posts is like that, he probably weighs 350 lbs.
and sits in front of his computer 24/7 buck ass naked. Those freaks
from Northern California are like that!"

This sounds like David Eduardo:


- http://216.77.188.54/coDataImages/p/...ders/32250/989...

- Hide quoted text -

- Show quoted text -


I B OC'Deed and Half-Crocked,

Yep that's me before I lost my Hair ) ~ RHF
  #27   Report Post  
Old January 17th 08, 01:56 AM posted to rec.radio.shortwave
RHF RHF is offline
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First recorded activity by RadioBanter: Jun 2006
Posts: 8,652
Default RHF = Idiocy & Brain Damage

On Jan 16, 3:41*am, IBOCcrock wrote:
On Jan 15, 9:31*pm, "Burr" wrote:





"Joe Analssandrini" wrote in message


...


Sir:


I can only say that I always find RHF's postings to be informative and
to the point. He has helped many, many people here including myself.
No one forces anyone to read his postings. If you, or anyone else, do
not wish to read them, just skip over them.


I'll continue to read his information gratefully and I am happy that
he is an active member here.


Joe


YES BUT,
* * * *He is very ugly, has hair hanging out his nose and ears, his eye
brows are grow together and he has two chins.


Burr


Hae you gotten caught again looking at porn on the Web?- Hide quoted text -

- Show quoted text -


I B OC'Deed and Half-Crock,

You seem to have a 'Fixation' about Looking at Porn
on the Web -based on- all your related postings.

~ RHF
  #28   Report Post  
Old January 17th 08, 02:07 AM posted to rec.radio.shortwave
RHF RHF is offline
external usenet poster
 
First recorded activity by RadioBanter: Jun 2006
Posts: 8,652
Default I Nominate "Michael Black" for Keeper of Secred and Holy FrequenctlyAsked Questions (FAQs) of the Rec.Radio.Shortwave Newsgroup

I Nominate "Michael Black" for Keeper of Secred and Holy
Frequenctly Asked Questions (FAQs) of the
Rec.Radio.Shortwave Newsgroup.

Seeking New FAQ/Intro Maintainers for rec.radio.shortwave
http://groups.google.com/group/rec.r...cf8ec73df6faad

He's Got The Right Stuff !

MB - Go For It - in all moderation ~ RHF
  #29   Report Post  
Old January 17th 08, 04:58 AM posted to rec.radio.shortwave
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Posts: 786
Default RHF = Idiocy & Brain Damage

On Jan 16, 12:20�pm, (Michael Black) wrote:
bpnjensen ) writes:
On Jan 16, 2:31=A0am, BCBlazysusan wrote:
On Jan 15, 10:50=A0pm, RHF wrote:


On Jan 15, 6:50=A0pm, wrote:


On Jan 15, 12:56 pm, wrote: Poor Roy, he must h=

ave been exposed to massive amounts of microwave
energy or RF energy. He simply cannot make a post without those
redundant cut n' paste links he deems important to life on this
planet.


What a goddamn dork!!!


+++++++++++++++++++++++


-=A0Keep in mind the guy was a government bureaucrat for 30 years.


Bureaucrat -nah- I was simply a low level US Civil Servant doing a
Job.


-ps- It was 32+ Years


- That explains why he acts the way he does.


Could Be . . .


- The arrogance and compulsive {with a} need to be in charge


Very True.


- (evidenced here by his self appointed moderator role) and


Clearly I am failing at that task : Based on this and other Posts
about me; and not about Shortwave Radio.


- his smug "I'm the smartest guy in the room" attitude.


Dang - You Got That Right -but- Then Again I do sign many of
my Posts "pomkia" - POMKIA =3D Plain Old Mister Know It All .


- In short, he's a caricature of himself - pompous, arrogant, self
- righteous, hypocritical


http://www.octanecreative.com/knowitall/jpgs/mr_kia.jpg


- (chronically scolding others for off topic posting while he is
- one of the worst offenders) and obnoxious


Dang - You Got That Right !


- the consummate {petty} bureaucrat.


Again - I was just a low level US Civil Servant.


- =A0Roy's 30 years as a government parasite


The Truth {Reality} is that the vast majority of US Civile Servants
are Good Decent Hard Working People who Earn their Salary.


- making the lives of people who paid his salary miserable
- prepared him well for his current role as
- resident pain in the ass.


Well at least I appear to have succeeded with you. ) ! ~ RHF
=A0.


RHF,
Don't let em' get you down. FWIW I have your back. I really need to
start posting posting more. I really miss Steve/Bryants
'conversations'....lol.....those were classics IMO back in the day.
Many great people IMO in here just a few bad apples. Ole' DXlover
waving a hand at you. :-)- Hide quoted text -


- Show quoted text -


Ditto too, and RHF, you're OK in my book - I may not always agree with
your politics (but sometimes do), but there is no shame at all in your
postings about radios, antennas and equipment, or how to use them.
The feebs who have criticized? �I doubt if they know a kilowatt from a
kilocycle.


Some bozo who constantly yammers on, posting when he usually has little
to say, posting links rather than real comments, posting in a completely
unreadable style, constantly changing subject headers, playing
"moderator" when his skill is so horrific that it only makes things
worse, and being a big source of the animosity here, well that defines
the state of the newsgroup. �"RHF" isn't the only one, but he certainly
enables the other junk posters.

Wade through the off topic posts, the political bickering and admonishments,
and there isn't much here. �Far better for the yammerers to be silent for
a time than to constantly spew. �And yes, you will see three or four
posters, including the bozo "RHF", in the thick of all that drivel.

There was a time when if someone asked a simple question, they'd be
told to look it up themselves. �But nowadays, this newsgroup is full
of people who do that work for the lazy, merely posting links. �And
when people do that, who's to know whether they know anything or not?
There is no value in posting such links, because the original poster
should be doing that work themselves. �But instead, we get all these
link posters, and nobody around to really address the question that
may not be properly asked.

The only reason this bozo RHF is getting accolades is because
the newsgroup has decayed so much that many have left, and a new
wave that doesn't know better has moved in. �SOmeone who can't keep
his mouth shut is bound to dominate a newsgroup, and that's what people
are reacting to. �Look between the lines, and there is little of substance
there, and the only reason he becomes a "valuable source" is because the
good posters of the old days have faded away, so there's nothing better
than a bozo posting links.

A newsgroup is not healthy if only a handful dominate. �Drive off a wide
range of readers, and the newsgroup declines, because as long as people
are reading a newsgroup, they may reply when they actually have something
to add, so some obscure topic gets a real answer instead of another
stupid link. �Or that person who only replies a few times a year may
have some obscure bit of knowledge that few know, so if they tune out,
there goes the knowledge.

It's telling that the bozo RHF never looks things up in this newsgroup,
he's constantly linking to other sources of information.

This is what the newsgroup used to be like, before the bozos and the village
idiots took over:

From: (Michael Black)
Subject: Double conversion Vs Triple conversion
Date: 2000/02/17
Message-ID:
X-Deja-AN: 587020050
References:
Organization: Communications Accessibles Montreal, Quebec Canada
Newsgroups: rec.radio.shortwave

In article , dan wrote:
All:
I am considering buying a new World Band reciever;
(- this may be my lifes work )
Does anyone know, in laymans terms, what �the advantages of a triple
conversion receiver Vs double conversion receiver are;
�and, if one is listening Just to world band, �is there a really good
choice of triple conversion receiver;
all things (antenna, location) being equal..
Really difficult to hear stations are the most interesting to try to
receive; Indonesia,
New Zealand on a bad night, WBCQ on Saturdays.. etc.
- Dan


How many conversions a receiver has is not a direct indication of
performance.

The whole point of superheterodyne receivers is to get the incoming
signal to a frequency where amplification and selectivity can
easily be accomplished.

The superhet is something like 80 years old, which is barely younger
than radio itself. When it was invented, the state of the technology
could only mean that the superhet would convert to a lower frequency.
It was easier to get amplification there, and since it was a fixed
frequency as opposed to variabl4e frequency if amplification took
place on the signal frequency, you wouldn't need constant readjustment.
Selectivity may have been a mere byproduct; �I know I've seen early
schematics of superhets where provides no selectivity, only amplification.
Of course, with time, selectivity became an important reason for
the superhet.

But once the superhet was invented, it became clear that there was
a problem. �In the conversion to another frequency, the IF (Intermediate
Freuqency), you'd also get an image frequency. �Basically, that
meant that anywhere you tuned the receiver, you would pick up two
signals, the one you want and one that was a side effect of the conversion..

With the relatively low frequencies used for the IFs in the early days,
the only way to get rid of the unwanted image frequency was to put
more selectivity on the signal frequency, which in some ways
the superhet was supposed to eliminate. �Usually there was no
problem in the �AM broadcast band, and even in the low shortwave
bands, because relatively simple front end selectivity could give
enough rejection of the image frequency. �But a lot of cheap
receivers from the old days bombed on the highest band, the one
that ended at 30Mhz, because there was way too little selectivity
in the front end to get rid of the image frequency.

Of course, the more expensive receivers did put more selectivity
in the front end, and suffered far less. �The HRO series were
manufacturered up into the sixties (or was it the late fifties?),
and they still had a 455KHz IF. �But they had two RF stages and
associated tuned circuits to get rid of the image frequency.

With time, somebody thought of the idea of double conversion. �Convert
the incoming signal to a frequency high enough that it would place
the image frequency far enough away that the front end would reject
it sufficiently, and then a second conversion to a frequency
where the real amplification and selectivity could take place. �Of
course, if the design wasn't done right, it could be horrible since
you now had two sets of image frequencies to get rid of, and of course
you added a second oscillator inside the receiver to generate
spurious signals.

Triple conversion was just an extension of that, though in some cases
it was used to add special features.

One of the problems of double, or triple, conversion is that in
that era it put a fair amount of amplification before the ultimate
selectivity of the receiver. �So the tuned circuits before the
final IF would take out the image frequency, but a strong signal not
that far from the desired signal would pass without attenuation,
and if it was strong enough it could overload one of the stages.

With time, technology allowed for a different implementation of
the superhet. �You could have good selectivity at a high frequency,
and of course tubes and later transistors got good enough that
they could amplify with no problem at high frequencies.

So there was a move back to single conversion receivers, with
the IF in the 9MHz range, or thereabouts. �The IF was far
enough away that only the strongest signals on the image frequency
could get by relatively simple front end selectivity. �And the
selectivity could be put right after the mixer, meaning that all
the rest of the receiver saw only the bandwidth of a single "channel".
The mixer was still vulnerable to overload, though there were
improvements in that area around the same time, but at least it
was reduced to only one mixer. �And in many cases the high IF
allowed for no amplification before the mixer, again helping
the receiver's overload resistance.

Of course, there were problems. �Having the IF in the middle of
the range the receiver was trying to tune was a problem. �And those
crystal filters could be expensive.

With time, mainly when ICs allowed for cheap synthesizers so the
local oscillator could operate at a high frequency and still be
stable, the first IF moved up above the 30MHz. �The whole shortwave
band could then be tuned without a gap, and there were other
good reasons for moving the IF there.

The problem was that a filter at 45MHz or so could be terribly
expensive, and it might even be difficult to get narrow selectivity
in that range.

So receivers moved back to double conversion. �The filter at the first
IF would be little wider than the widest selectivity desired, so
the rest of the receiver would have to deal with a relatively small
slice of spectrum. �And the IF was high enough that virtually
anything in the way of front end selectivity would reject the image
frequency, allowing for quite a bit of flexibility in the front
end design. �Of course, the overload resistance of the mixer
became an issue as the selectivity decreased in the front end; �it
had always been a problem, but image rejection had been a more
immediate need for that front end selectivity.

And of course, triple conversion also returned. �But it was for
things like passband tuning, rather than to deal with limited
technology.

The point to all this is that conversion is a trade-off. Triple conversion
will give you pass band tuning, but if not done carefully will give
you spurious responses. �But that triple conversion is giving you
a feature, better to be assesed on the basis of that feature, rather
than as an absolute. �If you wanted to pay the high price, a single
conversion receiver with a bank of filters of various bandwidths
operating at 45MHz or so would probably be best, since you don't
have to worry about the problems of multiple conversion. �But
people want multiple bandwidths and lower cost, so you end up
with double conversion receivers. �Likewise, they want poassband
tuning, so they end up with triple conversion.

But you can't compare two receivers by looking at how many conversions,
and say this one is better than that one because it has double (or triple
conversion). �You have to look at the overall design, and the specs.

As for scanners, that someone brought up in this thread, the need
for multiple conversions is a reflection of the wide frequency;coverage
that many of them provide, and the multiple conversions could be
seen in the same light as multiple conversions in receivers of
yesteryears. �They need it to get rid of the image frequencies.
The technology hasn't caught up enough with the needed range.

� � Michael


OK. This post requires temporary de-cloaking!

Will you please consider distributing to the group whatever you're
obviously on?

You start off complaining about RHF and people posting links, then you
cite a silly post from DiverDan about selecting a cheap portable as
being what this group should aspire to, and ramble into the most
esoteric post I think I've ever read on receiver design.

Wow. That's impressive. Can you say "tangential"?

After leaving this zoo for over 2.5 years (except for a few minor
incursions) I think I can say with certainty that though people like
Steve Lare (DXAce) and Roy Fisk (RHF) are often difficult to deal
with, they are clearly the most valuable contributors in RRS. Lare's
contributions to DXLD and BDXC are valuable resources in the
international DX community and his links to EiBi updates invaluable in
this post-ILG world. RHF's tireless efforts to disseminate antenna
info through his Yahoo group is a MONUMENTAL service to the community.
I don't like their politics, but they help keep this hobby alive in
difficult times. Yeah, they probably shouldn't post when drunk, but
none of the rest of us are really perfect, either.

Anyone who really believes these people are hurting the hobby by
providing useful links is someone the hobby would probably be better
off without.

Who knows? Maybe, if I stay away long enough, I'll gain the
perspective to understand what Telamon's contribution to the hobby
really is. Right now, I haven't got the faintest concept of why anyone
would read his posts.... ;-)

Re-cloaking,

MWBRYANT
  #30   Report Post  
Old January 17th 08, 08:58 AM posted to rec.radio.shortwave
external usenet poster
 
First recorded activity by RadioBanter: Jan 2008
Posts: 7
Default RHF = Idiocy & Brain Damage

D Peter Maus wrote:
oneway wrote:

D Peter Maus wrote:

wrote:

On Jan 15, 4:07 pm, D Peter Maus

There's a lot of personality, here, too. Truth is, Roy has most of
it. But if Roy chooses to make a career out of participating in this
group....so what? If he's got the time and the resources....God
Bless him.

The question is....what does it matter to YOU?


+++++++++++++++++++++++++++++++++++++++++
It matters because his compulsive posting of irrelevant bs has driven
away many shortwave enthusiasts who visit daily and contribute
regularly to the group. Most no longer bother to even read the group
much less post because they have long ago tired of the little clique
of posters who now dominate the group.

It's like the friendly neighborhood bar that everyone that mattered
once enjoyed gathering that gets taken over by a few obnoxious
drunks. The change in atmosphere is almost imperceptible because it
happens over time. One by one the regulars stop dropping in and soon
the only patrons are the obnoxious loud mouthed few and the bar soon
goes bankrupt.

So yes, it matters sir.




Then you serious need to refocus your priorities. If you can be run
off by one poster's style...I'm guessing shortwave wouldn't be your
best choice of avocation.



The question for you Peter, is why do posters like Roy, Burr, Steve
and others get a pass from you when they are the source for most of
the OT garbage on this group? My guess is that you secretly support
their politics and world views but don't want to admitt it here. You
didn't use to be like that in the good old days. You made mostly
useful contributions and rarely responded to the OT posts. Now you
almost encourage them. What happened?
(Hint: 'nothing happened' is not an acceptable answer)




Yeah, back in the 40's, I was quite the stickler for the rules. You
know, back in the good ol' days, Univac, tube routers, and secret
messages over AM radio to subversive forces identified only with decoder
rings....I was all about the topic, wasn't I.

Wow. Even I don't recognize me anymore. Perhaps that's why I can't get
laid.

Well, time for some new flannel shirts, eh?



:::::Hmmm....I wonder where the dog is......::::


Nice dodge. I guess the answer is yes, you do agree with them and that's
why they get a pass for disrupting the group with their BS.

BTW- The dog abandoned this group too. You can find him at one of the
Yahoo groups.
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