Date   

Re: Coax Loss

Rick Bennett
 

Scott, for what it is worth, I think you are making a good decision.  All of my coax is 8X and one run is over 100' (on HF antenna).

 

de KC0PET, Rick 


From: "Scott - nb0w"
To: 4sqrp@...
Sent: Tuesday, February 25, 2014 4:21:39 PM
Subject: Re: [4sqrp] Coax Loss

 

Thanks for all the replies. Sounds like I'll save the $100 and go with 8X.

Maybe I can use that $100 to get a Cyclone 40 or something fun like that. :)

Scott - nb0w

On 2/25/2014 3:12 PM, dave wrote:
> Scott,
>
> About the only time a difference of 0.6 dB would be detectable on the
> other end is if you and another station were going head-to-head trying
> to work that station, as in chasing DX or a contest. He might be able
> to pick you out a bit sooner with the bigger coax on your end. For
> normal rag chewing it would not matter at all. There is too much QSB,
> etc. for such a small difference to matter.
>
> On your end, you would be hard pressed to tell any difference. Yes,
> your RX signal level would be down a bit, and there is the possibility
> that on a very quiet band, such as 10m, it could matter. What matters
> is the signal to noise ratio. And since both the signal and the noise
> would be attenuated equally you'd not be able to tell it. Only if the
> band noise were below the receiver's inherent noise level would it
> matter. And that is rare on the HF bands.
>
> 73 de dave
> ab9ca/4
>
>
>
> On 2/25/14 1:50 PM, nb0w@... wrote:
>>
>>
>> I plan to replace two pieces of 20 year old coax once Spring finally
>> gets here. One would be for a 10, 15, 20m 3 element beam, and the
>> other for a 135' OCF "horse fence" dipole. As a starting point, I'm
>> looking at DX Engineering coax specs.
>>
>> Their "400 Max" is listed at .8db loss for 100ft at 30mhz.
>> The RG8X is listed at 1.4db loss for 100ft at 30 mhz.
>>
>> The 8X is about half price of the 400 on their pre built pieces, plus
>> it's much smaller, more flexible, and easier to route around in the
>> shack. On the other hand, that seems like a significant difference in
>> loss, until I think about how I only need 75' and most of my activity
>> is well lower than 30mhz (usually 20, 40 & 80m).
>>
>> I do run 100 watt SSB at times, but I'm mostly QRP.
>>
>> I'm not looking for a dissertation on DB losses, but I thought I'd ask
>> if you guys think in practical real world use, would either I, or the
>> receiving station be able to tell a difference in signal between those
>> two 75' pieces of coax? I know the 400 is "better", but I question how
>> much difference it would make (if any) in the practical sense. I can
>> get two pieces of 8x for the price of one 400.
>>
>> Thanks!
>> Scott - nb0w
>>
>>
>>
>>
>>



Re: Coax Loss

Scott - NB0W
 

Thanks for all the replies. Sounds like I'll save the $100 and go with 8X.

Maybe I can use that $100 to get a Cyclone 40 or something fun like that. :)

Scott - nb0w

On 2/25/2014 3:12 PM, dave wrote:
Scott,

About the only time a difference of 0.6 dB would be detectable on the other end is if you and another station were going head-to-head trying to work that station, as in chasing DX or a contest. He might be able to pick you out a bit sooner with the bigger coax on your end. For normal rag chewing it would not matter at all. There is too much QSB, etc. for such a small difference to matter.

On your end, you would be hard pressed to tell any difference. Yes, your RX signal level would be down a bit, and there is the possibility that on a very quiet band, such as 10m, it could matter. What matters is the signal to noise ratio. And since both the signal and the noise would be attenuated equally you'd not be able to tell it. Only if the band noise were below the receiver's inherent noise level would it matter. And that is rare on the HF bands.

73 de dave
ab9ca/4



On 2/25/14 1:50 PM, nb0w@scottm.cc wrote:


I plan to replace two pieces of 20 year old coax once Spring finally
gets here. One would be for a 10, 15, 20m 3 element beam, and the
other for a 135' OCF "horse fence" dipole. As a starting point, I'm
looking at DX Engineering coax specs.

Their "400 Max" is listed at .8db loss for 100ft at 30mhz.
The RG8X is listed at 1.4db loss for 100ft at 30 mhz.

The 8X is about half price of the 400 on their pre built pieces, plus
it's much smaller, more flexible, and easier to route around in the
shack. On the other hand, that seems like a significant difference in
loss, until I think about how I only need 75' and most of my activity
is well lower than 30mhz (usually 20, 40 & 80m).

I do run 100 watt SSB at times, but I'm mostly QRP.

I'm not looking for a dissertation on DB losses, but I thought I'd ask
if you guys think in practical real world use, would either I, or the
receiving station be able to tell a difference in signal between those
two 75' pieces of coax? I know the 400 is "better", but I question how
much difference it would make (if any) in the practical sense. I can
get two pieces of 8x for the price of one 400.

Thanks!
Scott - nb0w




Re: Coax Loss

WA0ITP
 

Oh Ya, happens all the time, i.e. the G5RV on other than the design band.

----------------------------------
Back to the bench, Winter's too valuable to waste.
I love this radio stuff !
72 WA0ITP
www.wa0itp.com
www.4sqrp.com

----- Original Message -----
From: "dave" <ho13dave@gmail.com>
To: <4sqrp@yahoogroups.com>; "Tim McDonough N9PUZ" <tim.n9puz@gmail.com>;
<nb0w@scottm.cc>
Sent: Tuesday, February 25, 2014 3:17 PM
Subject: Re: [4sqrp] Coax Loss



Surely no one uses coax to feed a non-resonant antenna?

That is the ham radio version of suicide!

73 de dave
ab9ca/4



On 2/25/14 3:01 PM, Tim McDonough N9PUZ wrote:


Scott --

One of the big differences if you do not have resonant antennas is the
SWR loss of each coax. What may seem trivial at a 1:1 SWR could be
significant at 10:1, etc.

You might make some comparisons here: <http://www.saarsham.net/coax.html>;

Tim N9PUZ

On 2/25/2014 1:50 PM, nb0w@scottm.cc wrote:
�

I plan to replace two pieces of 20 year old coax once Spring finally
gets here. One would be for a 10, 15, 20m 3 element beam, and the
other for a 135' OCF "horse fence" dipole.� As a starting point,�
I'm looking at DX Engineering coax specs.�


Their "400 Max" is listed at .8db loss for 100ft at 30mhz.
The RG8X is listed at 1.4db loss for 100ft at 30 mhz.

The 8X is about half price of the 400 on their pre built pieces,
plus it's much smaller, more flexible, and easier to route around in
the shack. On the other hand, that seems like a significant
difference in loss, until I think about how I only need 75' and most
of my activity is well lower than 30mhz (usually 20, 40 & 80m).

I do run 100 watt SSB at times, but I'm mostly QRP.

I'm not looking for a dissertation on DB losses, but I thought I'd
ask if you guys think in practical real world use, would either I,
or the receiving station be able to tell a difference in signal
between those two 75' pieces of coax? I know the 400 is "better",
but I question how much difference it would make (if any) in the
practical sense. I can get two pieces of 8x for the price of one 400.

Thanks!
Scott - nb0w




------------------------------------

4SQRP Website: http://4sqrp.com
OzarkCon is coming April 4-5, 2014 in Branson, MO
View Details at http://www.ozarkcon.com/index.phpYahoo Groups Links


Re: Coax Loss

dave <ho13dave@...>
 

Surely no one uses coax to feed a non-resonant antenna?

That is the ham radio version of suicide!

73 de dave
ab9ca/4

On 2/25/14 3:01 PM, Tim McDonough N9PUZ wrote:


Scott --

One of the big differences if you do not have resonant antennas is the
SWR loss of each coax. What may seem trivial at a 1:1 SWR could be
significant at 10:1, etc.

You might make some comparisons here: <http://www.saarsham.net/coax.html>;

Tim N9PUZ

On 2/25/2014 1:50 PM, nb0w@scottm.cc wrote:
Â

I plan to replace two pieces of 20 year old coax once Spring finally
gets here. One would be for a 10, 15, 20m 3 element beam, and the
other for a 135' OCF "horse fence" dipole. As a starting point,Â
I'm looking at DX Engineering coax specs.Â


Their "400 Max" is listed at .8db loss for 100ft at 30mhz.
The RG8X is listed at 1.4db loss for 100ft at 30 mhz.

The 8X is about half price of the 400 on their pre built pieces,
plus it's much smaller, more flexible, and easier to route around in
the shack. On the other hand, that seems like a significant
difference in loss, until I think about how I only need 75' and most
of my activity is well lower than 30mhz (usually 20, 40 & 80m).

I do run 100 watt SSB at times, but I'm mostly QRP.

I'm not looking for a dissertation on DB losses, but I thought I'd
ask if you guys think in practical real world use, would either I,
or the receiving station be able to tell a difference in signal
between those two 75' pieces of coax? I know the 400 is "better",
but I question how much difference it would make (if any) in the
practical sense. I can get two pieces of 8x for the price of one 400.

Thanks!
Scott - nb0w



Re: Coax Loss

Tim N9PUZ
 

Scott --

One of the big differences if you do not have resonant antennas is the SWR loss of each coax. What may seem trivial at a 1:1 SWR could be significant at 10:1, etc.

You might make some comparisons here:

Tim N9PUZ

On 2/25/2014 1:50 PM, nb0w@... wrote:
 

I plan to replace two pieces of 20 year old coax once Spring finally gets here. One would be for a 10, 15, 20m 3 element beam, and the other for a 135' OCF "horse fence" dipole. As a starting point, I'm looking at DX Engineering coax specs. 


Their "400 Max" is listed at .8db loss for 100ft at 30mhz.
The RG8X is listed at 1.4db loss for 100ft at 30 mhz.

The 8X is about half price of the 400 on their pre built pieces, plus it's much smaller, more flexible, and easier to route around in the shack. On the other hand, that seems like a significant difference in loss, until I think about how I only need 75' and most of my activity is well lower than 30mhz (usually 20, 40 & 80m).

I do run 100 watt SSB at times, but I'm mostly QRP.

I'm not looking for a dissertation on DB losses, but I thought I'd ask if you guys think in practical real world use, would either I, or the receiving station be able to tell a difference in signal between those two 75' pieces of coax? I know the 400 is "better", but I question how much difference it would make (if any) in the practical sense. I can get two pieces of 8x for the price of one 400.

Thanks!
Scott - nb0w


Re: Coax Loss

WA0ITP
 


GA Scott,
 
IMO I doubt that the other end of a QSO could hear the difference, that difference is too small to be detected by the human ear.  I've used 8X for years and it seems to be just fine.  The ease of use far outweighs the ~.6 in loss (in a perfect world) between the two.
 
---------------------------------
Back to the bench, Winter's too valuable to waste.
I love this radio stuff !
72   WA0ITP
www.wa0itp.com
www.4sqrp.com
 
 
 

----- Original Message -----
From: nb0w@...
Sent: Tuesday, February 25, 2014 1:50 PM
Subject: [4sqrp] Coax Loss

I plan to replace two pieces of 20 year old coax once Spring finally gets here. One would be for a 10, 15, 20m 3 element beam, and the other for a 135' OCF "horse fence" dipole. As a starting point, I'm looking at DX Engineering coax specs. 

Their "400 Max" is listed at .8db loss for 100ft at 30mhz.
The RG8X is listed at 1.4db loss for 100ft at 30 mhz.

The 8X is about half price of the 400 on their pre built pieces, plus it's much smaller, more flexible, and easier to route around in the shack. On the other hand, that seems like a significant difference in loss, until I think about how I only need 75' and most of my activity is well lower than 30mhz (usually 20, 40 & 80m).

I do run 100 watt SSB at times, but I'm mostly QRP.

I'm not looking for a dissertation on DB losses, but I thought I'd ask if you guys think in practical real world use, would either I, or the receiving station be able to tell a difference in signal between those two 75' pieces of coax? I know the 400 is "better", but I question how much difference it would make (if any) in the practical sense. I can get two pieces of 8x for the price of one 400.

Thanks!
Scott - nb0w


Coax Loss

Scott - NB0W
 

I plan to replace two pieces of 20 year old coax once Spring finally gets here. One would be for a 10, 15, 20m 3 element beam, and the other for a 135' OCF "horse fence" dipole. As a starting point, I'm looking at DX Engineering coax specs. 

Their "400 Max" is listed at .8db loss for 100ft at 30mhz.
The RG8X is listed at 1.4db loss for 100ft at 30 mhz.

The 8X is about half price of the 400 on their pre built pieces, plus it's much smaller, more flexible, and easier to route around in the shack. On the other hand, that seems like a significant difference in loss, until I think about how I only need 75' and most of my activity is well lower than 30mhz (usually 20, 40 & 80m).

I do run 100 watt SSB at times, but I'm mostly QRP.

I'm not looking for a dissertation on DB losses, but I thought I'd ask if you guys think in practical real world use, would either I, or the receiving station be able to tell a difference in signal between those two 75' pieces of coax? I know the 400 is "better", but I question how much difference it would make (if any) in the practical sense. I can get two pieces of 8x for the price of one 400.

Thanks!
Scott - nb0w


Re: Yahoo Troubles

Rick Bennett
 

I don't think these issues are unique to Yahoo.  I have fits with other web venues as well.  The computers I use all have IE, Chrome and Firefox installed on them.  If something doesn't work on one, I just try another one and usually at least one of them works.

 

I just did an experiment.  I logged into Yahoo on this particular computer on IE, Chrome and Firefox (this happens to be a satellite based ISP-Dell desktop PC with W7).  I also tried it on my iPhone on Safari.  Today everything works everywhere, I can log on, see my groups, open photos and files.  The mobile version makes it very difficult to find things but with persistence I found it all (I find the iPhone almost useless for anything other than taking phone calls, basic e-mail access and a simplistic view of today's wx, but that is my opinion).

 

But based on my experience, that will probably be different if I did the same thing in a week.  I can take my laptop computer and simply switch from my home ISP to a cell card and things will change; what worked in Chrome on my home wi-fi does not work on the cell card - same computer.  So I can only figure that these problems are very complex internet issues at all levels.  The problems may or may not be with Yahoo (or Google, or Centurylink, etc.)

 

 

Anyway, now that I am in the photos section I see there are more there than the last time I looked.  Lots of great projects out there in 4SQRP!

 

 

de KC0PET, Rick


From: "Michael McShan"
To: 4sqrp@...
Sent: Tuesday, February 25, 2014 10:47:49 AM
Subject: Re: [4sqrp] Yahoo Troubles

 

Yes, Yahoo has problems.  “Something” they’ve done recently has stopped Safari on the Mac from working properly with the groups.  I, too, have had to switch to Firefox.


73, Mike W5RST
OK City

On Feb 25, 2014, at 9:12 AM, Hajo Dezelski <dl1sdz@...> wrote:


Hello,

for the last months I was not able to sign in to Yahoo. I tried to reset my password, but it was never accepted.

Now I found a solution: I was using Chrome all the time. Now I switched to Firefox once. And it worked. Yahoo is still a mess. Don't like it.

72 de 
Hajo.
 



Re: Yahoo Troubles

Michael McShan
 

Yes, Yahoo has problems.  “Something” they’ve done recently has stopped Safari on the Mac from working properly with the groups.  I, too, have had to switch to Firefox.

73, Mike W5RST
OK City

On Feb 25, 2014, at 9:12 AM, Hajo Dezelski <dl1sdz@...> wrote:


Hello,

for the last months I was not able to sign in to Yahoo. I tried to reset my password, but it was never accepted.

Now I found a solution: I was using Chrome all the time. Now I switched to Firefox once. And it worked. Yahoo is still a mess. Don't like it.

72 de 
Hajo.
 


Re: Yahoo Troubles

Hajo Dezelski <dl1sdz@...>
 

Oooh,

I give up, I could sign in, but was not allowed to see the pictures.

72 de

Hajo

---
... indessen wandelt harmlos droben das Gestirn
... http://hajos-kontrapunkte.blogspot.com/


On Tue, Feb 25, 2014 at 4:12 PM, Hajo Dezelski <dl1sdz@...> wrote:
Hello,

for the last months I was not able to sign in to Yahoo. I tried to reset my password, but it was never accepted.

Now I found a solution: I was using Chrome all the time. Now I switched to Firefox once. And it worked. Yahoo is still a mess. Don't like it.

72 de 
Hajo

---
... indessen wandelt harmlos droben das Gestirn
... http://hajos-kontrapunkte.blogspot.com/


Yahoo Troubles

Hajo Dezelski <dl1sdz@...>
 

Hello,

for the last months I was not able to sign in to Yahoo. I tried to reset my password, but it was never accepted.

Now I found a solution: I was using Chrome all the time. Now I switched to Firefox once. And it worked. Yahoo is still a mess. Don't like it.

72 de 
Hajo

---
... indessen wandelt harmlos droben das Gestirn
... http://hajos-kontrapunkte.blogspot.com/


Re: Inductor types and applications

John Lonigro
 

Jim:

When you figure out what you need, KitsandParts.com usually has good prices and a good selection of toroids, as well as a nice inductance calculator.  No commercial interest - just a satisfied user.

72,

John AA0VE

On 02/25/2014 04:42 AM, Jim Compton wrote:
 
Jim,
Thanks for the information.  I need to get a few basic toroid sizes for my parts cabinet, but I've got to do some research on the most common and useful to have on hand.
Jim C.




Re: Inductor types and applications

James Compton
 

Jim,
Thanks for the information.  I need to get a few basic toroid sizes for my parts cabinet, but I've got to do some research on the most common and useful to have on hand.
Jim C.

-----Original Message-----
From: Jim Kortge
Sent: Feb 24, 2014 10:37 PM
To: 4sqrp@..., jdcompton@...
Subject: Re: [4sqrp] Inductor types and applications

On 2/24/2014 5:45 PM, jdcompton@... wrote:
>
>
> I'm going to build the Elliptic Low Pass Filter shown in the 4SQRP
> SAVXO article "How to Put the SAVXO on the Air and be Legal" . The
> schematic shows L1 as 0.9 microhenry and the picture shows a toroid.
> My question is: can an air-core coil inductor be used instead of a
> toroid?

Yes, an air core inductor would work just fine.

>
> By extension; a general discussion of inductor types would be very
> helpful for some of us who are not electronically savvy.

There are many good books out there that do that job. Also, probably
lots of good info via a Google search or Wikipedia.

In general,
> what are the advantages/disadvantages of using toroids in simple
> circuits, ie., simple qrp transmitters, low pass filters, etc.,
> instead of air-core coils.

Toroids are self shielding. Their flux fields are held very close to
the core, that doesn't happen with air wound inductors, so stray
coupling can be an issue.

Also, can manufactured inductors (I
> recently purchased some from Mouser shaped like high-wattage
> resistors) be used in place of toroids as long as the inductance
> values are the same?

Yes and no. If inductor Q isn't critical, then molded inductors will
work, but most often, high Q inductors are needed to keep losses at a
minimum, so toroidal or air-core inductors are used and preferred.
>
> I know there are basic differences in inductors, even when their
> inductance values are identical. Since air-core coils are so easy to
> build, I need to know their limitations in simple qrp applications.

See above.

> Thanks!

You are welcome.

72,

Jim, K8IQY



Re: Inductor types and applications

Chuck Carpenter
 

JD,

You have some good replies from other so need for repetition.

From another perspective, "back in the day" before common use of toroids that is, I've wound many air core and coils on formers.

And also used a lot of preformed coils in various spacings and sizes. You cut off what you needed for the project.

Unless you need an adjustable inductance though, I've found it much simpler and easier to wind toroids. As Jim noted, you don't have as much concern with mutual coupling between inductors. It's a bit of a challenge to wind 30 turns of #30 on a T25-6 core but all part of the QRP fun... :-)

Chuck Carpenter, W5USJ
EM22cv, Rains Co. TX


Re: Navigating the Yahoo Group site

Tim N9PUZ
 

A while back Yahoo improved their groups web interface and most people's opinion, mine included, is that it's awful.

Here's a link to Yahoo's help page on how to search: Yahoo Group Search

73,

Tim N9PUZ
4SQRP Group Co-Moderator

On 2/24/2014 4:54 PM, jdcompton@... wrote:
 

Is there a way to enter a search in a particular group for a subject instead of having to scroll through pages of conversations and topics?  I've tried to type in a subject to see if it's already been discussed, but haven't had any success yet.  As much discussion as in this group, it would be probable that some topics I have questions about have been covered before I joined the group.



Re: Inductor types and applications

Jim Kortge
 

On 2/24/2014 5:45 PM, jdcompton@mindspring.com wrote:


I'm going to build the Elliptic Low Pass Filter shown in the 4SQRP
SAVXO article "How to Put the SAVXO on the Air and be Legal" . The
schematic shows L1 as 0.9 microhenry and the picture shows a toroid.
My question is: can an air-core coil inductor be used instead of a
toroid?
Yes, an air core inductor would work just fine.


By extension; a general discussion of inductor types would be very
helpful for some of us who are not electronically savvy.
There are many good books out there that do that job. Also, probably lots of good info via a Google search or Wikipedia.

In general,
what are the advantages/disadvantages of using toroids in simple
circuits, ie., simple qrp transmitters, low pass filters, etc.,
instead of air-core coils.
Toroids are self shielding. Their flux fields are held very close to the core, that doesn't happen with air wound inductors, so stray coupling can be an issue.

Also, can manufactured inductors (I
recently purchased some from Mouser shaped like high-wattage
resistors) be used in place of toroids as long as the inductance
values are the same?
Yes and no. If inductor Q isn't critical, then molded inductors will work, but most often, high Q inductors are needed to keep losses at a minimum, so toroidal or air-core inductors are used and preferred.

I know there are basic differences in inductors, even when their
inductance values are identical. Since air-core coils are so easy to
build, I need to know their limitations in simple qrp applications.
See above.

Thanks!
You are welcome.

72,

Jim, K8IQY


Re: Inductor types and applications

Rick Bennett
 

Here is a tutorial I found that looks pretty good:

http://www.radio-electronics.com/info/data/inductors/inductor-types.php

I think the main disadvantage to air core inductors is size.  Another is that the air core will be more affected by things around it than a toroid.  In this case, though I would think it would be worth a try if board space is not an issue.  

I just took a piece of #24 wire and wound a 0.9 uH inductor with it.  It is about 1/2" diameter, 0.7" long and 10 turns.  I started with an on-line calculator and it gave me 1/2" x 0.8" x 12 turns.  I used my LC meter to adjust it to the right value.  Do you have an LC meter?

de KC0PET, Rick



From: jdcompton@...
To: 4sqrp@...
Sent: Monday, February 24, 2014 4:45:52 PM
Subject: [4sqrp] Inductor types and applications

 

I'm going to build the Elliptic Low Pass Filter shown in the 4SQRP SAVXO article "How to Put  the SAVXO on the Air and be Legal" .  The schematic shows L1 as 0.9 microhenry and the picture shows a toroid.  My question is: can an air-core coil inductor be used instead of a toroid?  


By extension; a general discussion of inductor types would be very helpful for some of us who are not electronically savvy.  In general, what are the advantages/disadvantages of using toroids in simple circuits, ie., simple qrp transmitters, low pass filters, etc., instead of air-core coils.  Also, can manufactured inductors (I recently purchased some from Mouser shaped like high-wattage resistors) be used in place of toroids as long as the inductance values are the same?  

I know there are basic differences in inductors, even when their inductance values are identical. Since air-core coils are so easy to build, I need to know their limitations in simple qrp applications.
Thanks!



FOXHUNT: Fox alert!

Dale Putnam
 




 

FOX ALERT!  
There are two Fox that are reportedly on the prowl.. and they love to tangle with hounds.
They have been reported to be heading into the 40 acre woods... and reportedly will be
seen somewhere between the trees marked 7.030 and 7.050... and this all comes to a
head about 7pm MT (0200z) Tuesday evening. ALL available hounds are encouraged to 
come help mix it up with these two sly and wily Fox.... W9CW and WC7S are on their badges
printed in the foxhole by the  Foxhole Certifying Committee. These two are known to be 
very agile and sly.. and extreme skill may be exhibited by them, care and caution is advised.

ok.. now for the serious stuff - 
1.4 The 40M Foxes will operate within +/- 10Khz of 7.040 MHz.  
That does NOT say anything about where the HOUNDS are to be.....

So be alert, and pay attention to the directions the Fox gives... 
What does the Fox say?   is a good line to remember.!!
Also.. one other aspect may be helpful, the fastest way to get through the pack,
is to get YOUR call heard by the Fox... and the BEST way to do that.. is to put YOUR call.. 
in the CLEAR.. either by giving your call at a time when NO one else is.. timing.. or by
putting it on a spot that does NOT have anyone else there...   IF you are in the middle of the 
pack  -  TIMING is a critical concern... if you are spread away from the pack even just a little..
calling additional times allows the FOX to tune to you... 
So there are two different strategies.. call often??? get away from the pack.. 
Call once>>> time it right and put it right in the pack. 
DON"T do both at the same time... but switch back and forth is good too.

Good Luck to all and to all a good HUNT!!
Catch us if you can...

The Wily West Fox
WC7S in Wy
 
 


Navigating the Yahoo Group site

James Compton
 

Is there a way to enter a search in a particular group for a subject instead of having to scroll through pages of conversations and topics?  I've tried to type in a subject to see if it's already been discussed, but haven't had any success yet.  As much discussion as in this group, it would be probable that some topics I have questions about have been covered before I joined the group.


Inductor types and applications

James Compton
 

I'm going to build the Elliptic Low Pass Filter shown in the 4SQRP SAVXO article "How to Put  the SAVXO on the Air and be Legal" .  The schematic shows L1 as 0.9 microhenry and the picture shows a toroid.  My question is: can an air-core coil inductor be used instead of a toroid?  

By extension; a general discussion of inductor types would be very helpful for some of us who are not electronically savvy.  In general, what are the advantages/disadvantages of using toroids in simple circuits, ie., simple qrp transmitters, low pass filters, etc., instead of air-core coils.  Also, can manufactured inductors (I recently purchased some from Mouser shaped like high-wattage resistors) be used in place of toroids as long as the inductance values are the same?  

I know there are basic differences in inductors, even when their inductance values are identical. Since air-core coils are so easy to build, I need to know their limitations in simple qrp applications.
Thanks!

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