Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #21   Report Post  
Old October 31st 08, 02:41 AM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Oct 2006
Posts: 527
Default Hammarlund SP-210 ?


"Richard Knoppow" wrote in message
m...

"Henry Kolesnik" wrote in
message ...


The civilian operating manual I mentioned in another
post is to be found at:
http://www.hammarlund.info/hamrmanu.html along with a great
deal of other Hammarlund stuff.


--

--
Richard Knoppow
Los Angeles
WB6KBL



  #22   Report Post  
Old October 31st 08, 03:31 AM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 774
Default Hammarlund SP-210 ?

Michael Black wrote:
And of course, one commonly written about trick in the old days was to
use a "useless" 400Hz transformer as an audio transformer, the operating
frequency being about where you'd want frequency response to start for
communication use. Since it moves the frequency up by six, the frequency
response is probably better at the higher frequencies.

That's only a useful trick, though, when 400Hz power transformers are
commonly available, and cheap because nobody can find a use for them.


I still see PLENTY of 400 Hz transformers coming out of the surplus
pipeline today, not to mention 400 Hz motors and brick power supplies.
You want some? I think I even have a box of 400 Hz fluorescent light
ballasts somewhere. Not even a little bit useful.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
  #23   Report Post  
Old November 1st 08, 09:02 PM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Dec 2006
Posts: 224
Default Hammarlund SP-210 ?

I haven't tested the impedance yet, need to find a pot, but I noticed
that the two 6F6es are connected as push pull triodes. I wonder why
they didn't use a pair of 45s?
Hank
"Scott Dorsey" wrote in message
...
Henry Kolesnik wrote:
Getting old is not recalling the alternatives offered, so I'm a dummy.
I
found the filament xfmr first and tried it but it reduced volume so I
assume my radio which is non-military doesn't have 600 ohms like the
military manual I have. So I guess mine is commercial, either a
SP-200-SX or more likely a SP-210-SX and I think it has a 3.2 ohm
output transformer.
I can't find any info and I wonder if anyone knows for sure on the
commercial models output transformer's impedance.


What is the DC resistance across the output?

If you want to know FOR SURE, put the output on a scope with a 1K pot
in
parallel with it... tune to interchannel noise, and note the location
of
the peaks on the scope. Crank the pot up until the level is exactly
half
of what it was, then measure the value of the pot.
--scott


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


  #24   Report Post  
Old November 2nd 08, 08:33 PM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Oct 2006
Posts: 527
Default Hammarlund SP-210 ?


"Henry Kolesnik" wrote in
message ...
I haven't tested the impedance yet, need to find a pot,
but I noticed that the two 6F6es are connected as push pull
triodes. I wonder why they didn't use a pair of 45s?
Hank


The 6F6 was a much newer tube at the time and is a
metal, octal base, tube. It has sufficient plate dissipation
and works well as a triode audio amp. The 45 also has 2.5V a
filament and is not a heater type cathode, meaning that it
needs a DC filiment source for audio use.
Triode audio amps have lower source impedance than
tetrodes when used without feedback which is an advantage in
driving variable load impedances like loudspeakers, and
generally more pleasant overload characteristics. The 6F6
was a good choice at the time and could also be used as a
driver.


--
--
Richard Knoppow
Los Angeles, CA, USA



  #25   Report Post  
Old November 4th 08, 01:24 AM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Dec 2006
Posts: 224
Default Hammarlund SP-210 ?

Rich
45s don't need DC for the filament...
They have been working fine on AC for years!
Hank
"Richard Knoppow" wrote in message
m...

"Henry Kolesnik" wrote in message
...
I haven't tested the impedance yet, need to find a pot, but I noticed
that the two 6F6es are connected as push pull triodes. I wonder why
they didn't use a pair of 45s?
Hank


The 6F6 was a much newer tube at the time and is a metal, octal
base, tube. It has sufficient plate dissipation and works well as a
triode audio amp. The 45 also has 2.5V a filament and is not a heater
type cathode, meaning that it needs a DC filiment source for audio
use.
Triode audio amps have lower source impedance than tetrodes when
used without feedback which is an advantage in driving variable load
impedances like loudspeakers, and generally more pleasant overload
characteristics. The 6F6 was a good choice at the time and could also
be used as a driver.


--
--
Richard Knoppow
Los Angeles, CA, USA





  #26   Report Post  
Old November 4th 08, 01:44 AM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Oct 2006
Posts: 527
Default Hammarlund SP-210 ?


"Henry Kolesnik" wrote in
message ...
Rich
45s don't need DC for the filament...
They have been working fine on AC for years!
Hank

Well, an ancient RCA tube handbook does list the 45 as
being for AC operated sets. It needs a center tapped
filiment transformer for cathode return although it could be
done with a center tapped resistor across the filiment. The
45 (AKA RCA UV-245) was an old and obsolete design when the
Super Pro was designed. Why do you think this tube is
superior to trioded connected 6F6's?


--

--
Richard Knoppow
Los Angeles
WB6KBL



  #27   Report Post  
Old November 4th 08, 02:28 AM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Dec 2006
Posts: 224
Default Hammarlund SP-210 ?

Richard
I don't know if the 45 triode is superior to a triode connected 6F6, I
was just wondering out loud at the keyboard. I know that audio
aficinianodos like 45s in class A but this is PP, B. It was a thought
that shouldn'thave made it to the keyboard, hi hi..
I took the beast to the hamfest but only found lookers and knob
twisters. Now I have the back breaking chore of bringing back to the
bench and checking the audio PP xfmr.
Hank
"Richard Knoppow" wrote in message
...

"Henry Kolesnik" wrote in message
...
Rich
45s don't need DC for the filament...
They have been working fine on AC for years!
Hank

Well, an ancient RCA tube handbook does list the 45 as being for AC
operated sets. It needs a center tapped filiment transformer for
cathode return although it could be done with a center tapped resistor
across the filiment. The 45 (AKA RCA UV-245) was an old and obsolete
design when the Super Pro was designed. Why do you think this tube is
superior to trioded connected 6F6's?


--

--
Richard Knoppow
Los Angeles
WB6KBL



  #28   Report Post  
Old November 4th 08, 03:29 AM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Dec 2006
Posts: 224
Default Hammarlund SP-210 ?

I just recalled I have a GR 583-A Output Power Meter wasting gravity and
if it still works I'll have the answer. If you Google it, you'll see
the one Sphere has for sale. Thanks for all the comments.
Hank
"Scott Dorsey" wrote in message
...
Henry Kolesnik wrote:
Getting old is not recalling the alternatives offered, so I'm a dummy.
I
found the filament xfmr first and tried it but it reduced volume so I
assume my radio which is non-military doesn't have 600 ohms like the
military manual I have. So I guess mine is commercial, either a
SP-200-SX or more likely a SP-210-SX and I think it has a 3.2 ohm
output transformer.
I can't find any info and I wonder if anyone knows for sure on the
commercial models output transformer's impedance.


What is the DC resistance across the output?

If you want to know FOR SURE, put the output on a scope with a 1K pot
in
parallel with it... tune to interchannel noise, and note the location
of
the peaks on the scope. Crank the pot up until the level is exactly
half
of what it was, then measure the value of the pot.
--scott


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


  #29   Report Post  
Old November 4th 08, 04:20 AM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Oct 2006
Posts: 527
Default Hammarlund SP-210 ?


"Henry Kolesnik" wrote in
message ...
I just recalled I have a GR 583-A Output Power Meter
wasting gravity and if it still works I'll have the answer.
If you Google it, you'll see the one Sphere has for sale.
Thanks for all the comments.
Hank

That will definitely give you the output impedance but
be careful not to overload it. There is something odd about
this. My BC-779 is in storage so I can't make resistance
measurements on the transformer. I think its time to dig it
out though.
I am afraid many people simply don't know what the
Super-Pro is or how good they are.
What part of the world are you in?

--

--
Richard Knoppow
Los Angeles
WB6KBL



  #30   Report Post  
Old November 4th 08, 01:23 PM posted to rec.radio.amateur.boatanchors
external usenet poster
 
First recorded activity by RadioBanter: Dec 2006
Posts: 224
Default Hammarlund SP-210 ?

Mine's in the trunk from the last hamfest with the power supply
connected so I have to carry both at once, the ps on top.
I'll get to it tomorrow, too many other things today..
I'm in Tulsa, OK
Hank
"Richard Knoppow" wrote in message
m...

"Henry Kolesnik" wrote in message
...
I just recalled I have a GR 583-A Output Power Meter wasting gravity
and if it still works I'll have the answer. If you Google it, you'll
see the one Sphere has for sale. Thanks for all the comments.
Hank

That will definitely give you the output impedance but be careful
not to overload it. There is something odd about this. My BC-779 is in
storage so I can't make resistance measurements on the transformer. I
think its time to dig it out though.
I am afraid many people simply don't know what the Super-Pro is or
how good they are.
What part of the world are you in?

--

--
Richard Knoppow
Los Angeles
WB6KBL



Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
WTD - HAMMARLUND 50 uuF Bill Turner[_2_] Equipment 0 February 14th 08 05:27 AM
FA: Hammarlund HQ-215 Larry McGee Boatanchors 0 October 31st 07 12:38 AM
FS: Hammarlund BC-779 JRS Boatanchors 0 February 14th 05 01:32 AM
FS: Hammarlund BC-779 JRS Swap 0 February 14th 05 01:31 AM
Hammarlund HQ-170 Jim Hackett Shortwave 9 February 2nd 05 01:59 AM


All times are GMT +1. The time now is 06:21 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017