Date   

Re: SDR radios

peatmoss - ki6ssi
 

http://websdr.org/ is decent, not a lot of radios but works well


SDR radios

davetelling .
 

Which SDR websites do you use to listen to your TX? I googled a bit, but didn't find that much.

Perhaps I'm looking for the wrong thing?

I'd like to find out, as QSO's are very hard to get nowadays.


Re: Antenna selection

Doug W
 

I just assembled the qrpguys EFHW mini tuner and have about 65' of 22awg wire shot up into a tree,  I was going for cheap and easy.  I also bought the dummy load/power meter and am very happy with both.  No QSO's yet but I just picked up a few muddled rag chewers here and there.


Re: BITX40 without Raduino?

William R Maxwell
 

Google Eamon Skelton's EI9GQ webpage for details of a Huff'nPuff stabilised VFO - and a host of other useful project concepts.

Bill, VK7MX


On 13/04/2017 6:55 AM, Jack Purdum via Groups.Io wrote:
I am unfamiliar with this one. I have one based on the AD9850 which I used for the Forty-9er and Antenna Analyzer projects. You can see these at:


and


Write to Farrukh before ordering, as I don't know the status of his board situation.

Jack, W9TEE


From: PY2CSH <csrabak@...>
To: BITX20@groups.io
Sent: Wednesday, April 12, 2017 4:39 PM
Subject: Re: [BITX20] BITX40 without Raduino?

Hi Jack!
Do you more info that you could share about this specific Huff-&-Puff stabilized Vackar VFO?
I'm also think this is a viable solution and searching for it in order not to reinvent the wheel!
73 de Cesar, PY2CSH





Re: The Users User Manual

John Smith
 

OK. So now that the instructions have been updated, and calibrating the displayed frequency offset, spatial orientation of some parts, and the stereo jack wiring points have been talked about. I have run out of important topics that some people would appreciate elaborating on or clearing up. 

I am opening this thread up to anyone who would like to add to it with building tips or fixes not yet documented. And focusing on getting up and running and off to a good start.

For example, you can use a phone or tablet and a frequency generator app to generate a 1khz loud tone, and hold your microphone up to the phone speaker to obtain a "full" power reading on your watt meter. Conversational SSB will average less than half of this "full" power reading. In case you were expecting more.

If you are using an antenna tuner, you can also use the microphone held up to the to the tone generator to adjust for full deflection of your signal on a SWR meter while adjusting your matching device for lowest SWR.

It's a simple tip to help get you up and running right away. And if you want, you could make the Raduino inject a tone into the mic line to do the same thing.

Converting the BITX40 for CW operation can be complicated. But adding a "TUNE" button with a tone generated by the raduino is an easier hack and might be worth the effort. If there is an interest in this one, we might be able to encourage Jerry to come back and tell us how he would do it. 


Re: BITX40 without Raduino?

Jack Purdum <econjack@...>
 

I am unfamiliar with this one. I have one based on the AD9850 which I used for the Forty-9er and Antenna Analyzer projects. You can see these at:

www.farrukhzia.com/k2zia 

and


Write to Farrukh before ordering, as I don't know the status of his board situation.

Jack, W9TEE


From: PY2CSH <csrabak@...>
To: BITX20@groups.io
Sent: Wednesday, April 12, 2017 4:39 PM
Subject: Re: [BITX20] BITX40 without Raduino?

Hi Jack!
Do you more info that you could share about this specific Huff-&-Puff stabilized Vackar VFO?
I'm also think this is a viable solution and searching for it in order not to reinvent the wheel!
73 de Cesar, PY2CSH




Re: BITX40 without Raduino?

PY2CSH
 

Hi Jack!

Do you more info that you could share about this specific Huff-&-Puff stabilized Vackar VFO?

I'm also think this is a viable solution and searching for it in order not to reinvent the wheel!

73 de Cesar, PY2CSH



Re: Running 24VDC into IRF510. Is there a down side?

John Backo
 

Remember that heat is the biggest enemy you have. You can't see it. You don't realize
it is a problem until suddenly things go haywire. It is always present no matter how you use the rig.

Always account for the heat generated by imagining and preparing for the worst case conditions.
That means a more than adequate sink and limiting the duration of the current draw. The MOSFETS
don't like heat, period. And they all have very poor heat transfer characteristics. For instance, the
derating of the IRF510 is 0.29W per deg C!

AF is right.

john
AD5YE


Re: Running 24VDC into IRF510. Is there a down side?

College Professor Simon Thompson <nwccenglishprofessor@...>
 

I would guess so; I would think that all RF finals will not be more than 50 per cent efficient, so even with a resonant antenna, current means heat.

On Apr 12, 2017, at 11:07 AM, John Beasley <john@...> wrote:

So i have my unit up and running on a home built a 40 Meter Dipole that is showing a completely flat SWR on my meter. I was doing some testing from here in Oregon to the WebSDR down in the bay area and last night was able to hear myself only when I fed 24V into the PA. The audio was pretty good and I was happily surprised at my success. I did not notice any excess heat being generated by the IRF510  and my meter was averaging around 10 watts output with my regular talking voice. I have ordered an additional heat sink and some replacement IRF510's just to be on the safe side.

My question is that if my SWR is kept flat and I make sure not to transmit into a non resonant antenna. Do i really need to worry about burning up the IRF510 with the stock heat sink?

Thanks,

John Beasley

KG7UMN






Re: Running 24VDC into IRF510. Is there a down side?

John Beasley
 

Okay thanks for the advice Farhan.

 

I will hold up on the long winded rag chew until I have my beefy heat sink and replacement finals sitting on the bench. I still think I am going to plan on my final setup having an adjustable voltage regulator for the PA portion of the system so I put a little fire to the wire when the situation calls for it.

 

73’s

John Beasley

KG7UMN

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Ashhar Farhan
Sent: Wednesday, April 12, 2017 11:15 AM
To: BITX20@groups.io
Subject: Re: [BITX20] Running 24VDC into IRF510. Is there a down side?

 

some day, you will wax eloquent about that fishing trip for 10 minutes and smoke the ol' 510!

 

- f

 

On Wed, Apr 12, 2017 at 11:37 PM, John Beasley <john@...> wrote:

So i have my unit up and running on a home built a 40 Meter Dipole that is showing a completely flat SWR on my meter. I was doing some testing from here in Oregon to the WebSDR down in the bay area and last night was able to hear myself only when I fed 24V into the PA. The audio was pretty good and I was happily surprised at my success. I did not notice any excess heat being generated by the IRF510  and my meter was averaging around 10 watts output with my regular talking voice. I have ordered an additional heat sink and some replacement IRF510's just to be on the safe side.

My question is that if my SWR is kept flat and I make sure not to transmit into a non resonant antenna. Do i really need to worry about burning up the IRF510 with the stock heat sink?

Thanks,

John Beasley

KG7UMN

 

 

 

 


Re: Running 24VDC into IRF510. Is there a down side?

Ashhar Farhan
 

some day, you will wax eloquent about that fishing trip for 10 minutes and smoke the ol' 510!

- f

On Wed, Apr 12, 2017 at 11:37 PM, John Beasley <john@...> wrote:

So i have my unit up and running on a home built a 40 Meter Dipole that is showing a completely flat SWR on my meter. I was doing some testing from here in Oregon to the WebSDR down in the bay area and last night was able to hear myself only when I fed 24V into the PA. The audio was pretty good and I was happily surprised at my success. I did not notice any excess heat being generated by the IRF510  and my meter was averaging around 10 watts output with my regular talking voice. I have ordered an additional heat sink and some replacement IRF510's just to be on the safe side.

My question is that if my SWR is kept flat and I make sure not to transmit into a non resonant antenna. Do i really need to worry about burning up the IRF510 with the stock heat sink?

Thanks,

John Beasley

KG7UMN






Running 24VDC into IRF510. Is there a down side?

John Beasley
 

So i have my unit up and running on a home built a 40 Meter Dipole that is showing a completely flat SWR on my meter. I was doing some testing from here in Oregon to the WebSDR down in the bay area and last night was able to hear myself only when I fed 24V into the PA. The audio was pretty good and I was happily surprised at my success. I did not notice any excess heat being generated by the IRF510  and my meter was averaging around 10 watts output with my regular talking voice. I have ordered an additional heat sink and some replacement IRF510's just to be on the safe side.

My question is that if my SWR is kept flat and I make sure not to transmit into a non resonant antenna. Do i really need to worry about burning up the IRF510 with the stock heat sink?

Thanks,

John Beasley

KG7UMN





Re: Antenna selection

Jack Purdum <econjack@...>
 

Ok...it's not my antenna. The world's largest amateur antenna belongs to OH8X in Sweden (Radio Arcala) and recently came down in a violent storm. Many amateurs want to know if it fell into Russia or Norway.

Jack, W8TEE



From: Jerry Gaffke via Groups.Io <jgaffke@...>
To: BITX20@groups.io
Sent: Wednesday, April 12, 2017 1:09 PM
Subject: Re: [BITX20] Antenna selection

I'm happy with the EFHW-8010 from Danny Horvat.  Google it.  EHam gives it a 5.0/5 with 44 reviews.   QST March of 2016 gave it a thumbs up too.  Efficient over many bands, and easier to put up than a dipole.  Go for the 4010 if you have limited space.  Substitute magnet wire if you have to tie into the neighbor's tree (magnet wire will affect the SWR).  Ideal for portable ops.  Though Jacks yagii might have more gain if you can figure out how to turn it to the proper direction.



Re: Antenna selection

Jerry Gaffke
 

I'm happy with the EFHW-8010 from Danny Horvat.  Google it.  EHam gives it a 5.0/5 with 44 reviews.   QST March of 2016 gave it a thumbs up too.  Efficient over many bands, and easier to put up than a dipole.  Go for the 4010 if you have limited space.  Substitute magnet wire if you have to tie into the neighbor's tree (magnet wire will affect the SWR).  Ideal for portable ops.  Though Jacks yagii might have more gain if you can figure out how to turn it to the proper direction.


Re: Antenna selection

Allard PE1NWL
 

On Wed, April 12, 2017 15:38, KC3EJC-Shawn wrote:
Which loop are you using Allard?
I'm using a homebrew hex shaped loop, made of 15mm copper pipe.
I used 6 pipes, each 1m long, and soldered them together in a hex shape.
So it´s amost a circle with 1.2m diameter.
On the top side I installed a motor-driven 0-350 pF variable capacitor.
It tunes to 1:1 SWR. But, as usual with magloop antenna's, the bandwidth
is only 15kHZ or so. So you need to re-tune the antenna very often,
therefore a motor-driven tuning cap is recommended.

There's a lot of information about magloops on the net, for example this one:
https://amrron.com/2015/07/24/home-made-high-power-magnetic-loop-antennas/

But there are many many more sites with useful information and building tips.
Just google for "magnetic loop antenna".

73, Allard PE1NWL


Re: The Users User Manual

John Smith
 

Well... I guess he's planning to respond by mail.


Re: Antenna selection

davetelling .
 

i would probably find 5W adequate with an antenna like that, too!


Re: Antenna selection

Jack Purdum <econjack@...>
 

I find my 5W adequate when I switch over to this antenna:





From: College Professor Simon Thompson <nwccenglishprofessor@...>
To: BITX20@groups.io
Sent: Wednesday, April 12, 2017 12:15 PM
Subject: Re: [BITX20] Antenna selection

The KX3 Yahoo forum always has interesting conversations about how to get the most for the least in terms on antennas. It is very hard to beat a resonant dipole for efficiency and portability and simplicity.

On Apr 12, 2017, at 08:52, davetelling . <davetelling@...> wrote:

To get some idea of possible portable performance, I tried a 43 foot-long wire, driven with a 9:1 balun, and being fed with about 15 ft. of coax, and no radials. the feedpoint is about 12ft above ground, and the and point is about 15 feet above ground. I did some A/B testing with my IC-718 (running through an antenna tuner) and was surprised to find that some stations came in better with the long-wire, and some came in better with the 40m OCF dipole. I am assuming that this is because of the different "lobes" of the two antennas' radiation patterns. I wish I had a simple way to run the 43ft wire vertically, but so far, nothing easily presents itself. However, it looks as if the 43ft wire/balun combo might make a compact portable antenna. It is interesting the amount of discussion about 4:1 vs. 9:1, counterpoise vs. no counterpoise (the coax shield becomes the "counterpoise") etc., but I am interested in a compact, easily deployed antenna that works acceptably for occasional portable operation.




Re: Antenna selection

College Professor Simon Thompson <nwccenglishprofessor@...>
 

The KX3 Yahoo forum always has interesting conversations about how to get the most for the least in terms on antennas. It is very hard to beat a resonant dipole for efficiency and portability and simplicity.

On Apr 12, 2017, at 08:52, davetelling . <davetelling@...> wrote:

To get some idea of possible portable performance, I tried a 43 foot-long wire, driven with a 9:1 balun, and being fed with about 15 ft. of coax, and no radials. the feedpoint is about 12ft above ground, and the and point is about 15 feet above ground. I did some A/B testing with my IC-718 (running through an antenna tuner) and was surprised to find that some stations came in better with the long-wire, and some came in better with the 40m OCF dipole. I am assuming that this is because of the different "lobes" of the two antennas' radiation patterns. I wish I had a simple way to run the 43ft wire vertically, but so far, nothing easily presents itself. However, it looks as if the 43ft wire/balun combo might make a compact portable antenna. It is interesting the amount of discussion about 4:1 vs. 9:1, counterpoise vs. no counterpoise (the coax shield becomes the "counterpoise") etc., but I am interested in a compact, easily deployed antenna that works acceptably for occasional portable operation.



Re: Antenna selection

davetelling .
 

To get some idea of possible portable performance, I tried a 43 foot-long wire, driven with a 9:1 balun, and being fed with about 15 ft. of coax, and no radials. the feedpoint is about 12ft above ground, and the and point is about 15 feet above ground. I did some A/B testing with my IC-718 (running through an antenna tuner) and was surprised to find that some stations came in better with the long-wire, and some came in better with the 40m OCF dipole. I am assuming that this is because of the different "lobes" of the two antennas' radiation patterns. I wish I had a simple way to run the 43ft wire vertically, but so far, nothing easily presents itself. However, it looks as if the 43ft wire/balun combo might make a compact portable antenna. It is interesting the amount of discussion about 4:1 vs. 9:1, counterpoise vs. no counterpoise (the coax shield becomes the "counterpoise") etc., but I am interested in a compact, easily deployed antenna that works acceptably for occasional portable operation.