Date   

Re: 43SQRP net

w2sh@...
 

Paul,


I think this may have been the first time I've copied your sig.  I understand that you had had some problems with a new rig, but whatever antenna you're using was doing FB.


I'll be QRV for the Second Sunday Sprint and hope you will be also. 


We're getting a lot of snow today and if it amounts to the 12-15" predicted, then that will blanket my in-ground radials and considerably diminish their effectiveness.  (The purpose of those radials is to harvest the radiation from the adjacent vertical antenna that splashes on the nearby ground and send it back to the antenna's feedpoint for "recycling"; a foot of water-permeated snow is an unwanted rf sponge).


72,


Charles (aka Chas), W2SH



From: Paul Smith on behalf of Paul Smith
Sent: Wednesday, February 8, 2017 10:08 PM
To: Charles Moizeau; 4sqrp@...
Subject: Re: 43SQRP net
 

Thanks for the report Charles,

I was getting some thunderstorm static as well. not sure from where but it was there

de Paul N0NBD


Sent from Outlook




From: Charles Moizeau
Sent: Thursday, February 9, 2017 2:13 AM
To: 4sqrp@...; Paul Smith
Subject: Re: 43SQRP net
 

Condx in NJ are very noisy with a major snow storm arriving here in six hours.  At 0130Z-ish I heard Wayne at 449.  Normally WA9PWP is the sig champ, but I didn't hear him.  Surprisingly, the other Paul, N0NBD, was nearly 569.


Charles, W2SH 






From: 4sqrp@... <4sqrp@...> on behalf of Paul Smith psmith61@... [4sqrp] <4sqrp@...>
Sent: Wednesday, February 8, 2017 8:57 PM
To: 4sqrp@...
Subject: [4sqrp] 43SQRP net
 
 

WOW I had a bunch of noise here tonight I did get 

WA0ITP Terry

WA8PWP Paul

WN0WWY Dale.

Thanks Terry for the relay.de Paul N0NBD


Sent from Outlook


Re: Member List

wi4t@...
 

I am one of the new guys - WI4T (Greg) from near Jerico Springs Missouri and I am coming to OzarkCon...  just saying :>)

I have been a ham for 30 years and am currently installing a 90' Rohn 25 if I can find a climber (I climb but had heart surgery 1 year ago and trying to decide if I should climb that high).   Also I have ordered a LM-470 which should be here in a month or so for my Cubex Mark IV extended boom quad (30 foot boom with 4 - 26 foot spreaders.  Should do a good job on QRP.

I look forward to meeting people at OzarkCon!

Greg


Re: Pixie success

Curt
 

Will be QRV over next few days with "Sea Squirt" pixie clone near 7.118 with 1/2W. Will post QRPspots when active. Looking for other pixie clone ops.

72, Curt KB5JO


Re: Failed IRF510 in BJ

Curt
 

The IRF510 can take a large current from drain to source, and get very hot without damage -- I learned this the 'hot way' in connecting my Magic Box up to a tuna tin 2 type keying circuit (that has bias on its key interface) from a transmitter I had copied from N5IB (interesting this was the original BJ version!).  Just because the IRF510 got very hot does not mean it is dead -- this would likely gate damage to the gate to be dead in a normal 12 volt PA application.  I hope you tried to use the BJ after discovery of the hot device?  No need to add to the email chain if the device is dead, and is being replaced. 

everyone should keep building in spite of this kind of issues -- it is part of the adventure. 

73 Curt


Re: Failed IRF510 in BJ

n5ib_2
 

I forgot to address the last question.

Ought not be a one-time protection.
The IRF510 is rated 100V Drain-Source breakdown, and the gate leakage is specified at a up to +/- 20V Gate to Source. So "normal" reverse polarity (due to a short circuit between the headphones - hi) shouldn't damage it.

Jim, N5IB


---In 4sqrp@..., <djwilcox01@...> wrote :
 Does reverse voltage cause the IRF510 to short out but still pass voltage when the voltage polarity is corrected? It is a ONE TIME protection? Important to know for all of us who might use this form of protection in the future.


Re: Failed IRF510 in BJ

n5ib_2
 

Very likely not a "dead short" failure. The gate structure isn't suposed to pass current at all, so even if it's compromised it may end up being a "lower" resistance path. To make a non-heatsinked TO-220 really hot doesn't take much current. The IRF510 junction-to-ambient thermal resistance is spec'ed at 62 deg C per W. So a couple watts gets you better than a 100 dec C rise. And 2 W at 12 V is just 170 mA or so. That would be some 4 amp-hr per day drained from your battery.

Now, that doesn't take into account heat that is transferred away via the soldered pins, but even if that reduced the temperature rise by a factor of 10, you could get a 50 deg C rise above ambient (90 F - pretty hot to touch) with 8 W. That would be less than 700 mA and wouldn't blow the 1 A fuse.

It would be an interesting and useful interesting data point if you could do a quick measurement of that current before you make the repairs, just to test the above theory.

In normal operation the voltage drop, Source to Drain, is so small with the device fully turned on that the power dissipation is very small as well. With an on-resistance of less than half an ohm, the 750 mA Tx current will cause less than 0.4V drop, and dissipate less than 300 mW. And, in theory, there's no current at all Gate to Source.

Proverb ---  "In theory, there is no difference between theory and practice, but in practice ....."

Jim, N5IB


Failed IRF510 in BJ

David Wilcox
 

Thanks for the replies. A few questions.

Since the IRF510 failed into short mode why didn't it blow the 1 amp fuse in the line? The BJ was connected to a large JetSki (like a motorcycle) battery that I use in the shack in the winter to keep it active for the next season.

Why did it continue to pass voltage to the BJ if it was shorted? A friend of mine sent me a couple of articles as to why mosfets fail but they didn't address these issues. It sure got hot though but no smoke let out. I discovered it being hot by mistake touching it while looking for bad solder joints.

I touched the case of my MFJ 969 antenna tuner before and during handling the IRF510 instead of wearing my wrist strap. My feet are on the metal base of an elevated architects chair and not rubbing on the carpet. Humidifier on.

I will be up front with every one here. I did reverse the voltage by mistake a few days before this all happened. No smoke. Short prayer of thanks for those wise enough to protect the elderly and stupid. Then went on to use the BJ and have fun. Does reverse voltage cause the IRF510 to short out but still pass voltage when the voltage polarity is corrected? It is a ONE TIME protection? Important to know for all of us who might use this form of protection in the future.

Dave K8WPE


Re: Member List

J.K. Wright
 

Been to Grayling once- left town in a canoe and went to Oscoda!!! Great area, but a bit remote. Nowhere to charge the batteries:)

On Feb 8, 2017 10:30 PM, "Bill Cromwell wrcromwell@... [4sqrp]" <4sqrp@...> wrote:
 

Here ya go...

Move OzarkCon to Grayling Michigan!

73,

Bill KU8H

On 02/08/2017 09:07 PM, David Martin davemrtn@... [4sqrp] wrote:
>
> That would be a 'historic' OzarkCon event !
>
> How do we make it happen !!! ????
>
> David Martin - NA1MH <https://www.qrz.com/lookup/na1mh> - Mountain
> Home, Ar. -----------------------------------------
> On 2/8/2017 19:41, ktalbott ktalbott@... [4sqrp] wrote:
>> It would be interesting to see them all at Ozarkcon!
>> Ken ke4rg
>>
>>
>> Sent from Samsung Mobile
>>
>>
>>
>> -------- Original message --------
>> From: "Johnny Matlock jomatlock@... [4sqrp]"
>> <4sqrp@...>
>> Date: 02/08/2017 5:54 PM (GMT-05:00)
>> To: 4sqrp@...,davemrtn <davemrtn@...>
>> Subject: Re: [4sqrp] Member List
>>
>>
>> Look out SKCC here we come!!
>> Thanks for the info Dave
>> Johnny AC0BQ
>> On Wed, Feb 8, 2017 at 1:40 PM davemrtn davemrtn@...
>> <mailto:davemrtn@centurytel.net> [4sqrp] <4sqrp@...
>> 4sqrp@...>> wrote:
>>
>> WOW !!!
>>
>> I see the 4SQRP member count very recently surpassed 1300.
>>
>> Way to go 4SQRP team and members.
>>
>> David -NA1MH
>>
>>
>>
>> Sent from my Verizon, Samsung Galaxy smartphone
>>
>> --
>> Sent from Gmail Mobile
>
>

--
bark less - wag more


Re: Member List

Ken Talbott
 

Shhhh!  Don’t tell them about the great door prizes at the banquet.  Who wouldn’t drive 10 or 12 hours for a new rig?

Ken ke4rg

 

From: David Martin [mailto:davemrtn@...]
Sent: Wednesday, February 8, 2017 9:08 PM
To: 4sqrp@...; ktalbott
Subject: Re: [4sqrp] Member List

 

That would be a 'historic' OzarkCon event !

How do we make it happen !!!   ????

David Martin - NA1MH - Mountain Home, Ar. -----------------------------------------

On 2/8/2017 19:41, ktalbott ktalbott@... [4sqrp] wrote:

 

It would be interesting to see them all at Ozarkcon!

Ken ke4rg

 

 

Sent from Samsung Mobile




-------- Original message --------
From: "Johnny Matlock jomatlock@... [4sqrp]" <4sqrp@...>
Date: 02/08/2017 5:54 PM (GMT-05:00)
To: 4sqrp@...,davemrtn
Subject: Re: [4sqrp] Member List


 

Look out SKCC here we come!!

Thanks for the info Dave

Johnny AC0BQ 

On Wed, Feb 8, 2017 at 1:40 PM davemrtn davemrtn@... [4sqrp] <4sqrp@...> wrote:

 

WOW !!!

 

I see the 4SQRP member count very recently surpassed 1300.

 

Way to go 4SQRP team and members.

 

David -NA1MH

 

 

 

Sent from my Verizon, Samsung Galaxy smartphone

--

Sent from Gmail Mobile

 


Re: Member List

David Martin <davemrtn@...>
 

In fact if someone wants to see where people have come from to attend OzarkCon, just look at this web page.......


www.ozarkcon.com/attendanceHistory



David Martin - NA1MH - Mountain Home, Ar. -----------------------------------------

On 2/8/2017 22:01, Tim McDonough N9PUZ tim.n9puz@... [4sqrp] wrote:
 

There are people who come to OzarkCon from Michigan now! Why move?

:-) Tim N9PUZ

On 2/8/2017 9:28 PM, Bill Cromwell wrcromwell@... [4sqrp] wrote:
>
>
> Here ya go...
>
> Move OzarkCon to Grayling Michigan!
>
> 73,
>
> Bill KU8H
>
> On 02/08/2017 09:07 PM, David Martin davemrtn@... [4sqrp] wrote:
>>
>> That would be a 'historic' OzarkCon event !
>>
>> How do we make it happen !!! ????
>>
>> David Martin - NA1MH - Mountain
>> Home, Ar. -----------------------------------------
>> On 2/8/2017 19:41, ktalbott ktalbott@... [4sqrp] wrote:
>>> It would be interesting to see them all at Ozarkcon!
>>> Ken ke4rg
>>>
>>>
>>> Sent from Samsung Mobile
>>>
>>>
>>>
>>> -------- Original message --------
>>> From: "Johnny Matlock jomatlock@... [4sqrp]"
>>> <4sqrp@...>
>>> Date: 02/08/2017 5:54 PM (GMT-05:00)
>>> To: 4sqrp@...,davemrtn
>>> Subject: Re: [4sqrp] Member List
>>>
>>>
>>> Look out SKCC here we come!!
>>> Thanks for the info Dave
>>> Johnny AC0BQ
>>> On Wed, Feb 8, 2017 at 1:40 PM davemrtn davemrtn@...
>>> [4sqrp] <4sqrp@...
>>> > wrote:
>>>
>>> WOW !!!
>>>
>>> I see the 4SQRP member count very recently surpassed 1300.
>>>
>>> Way to go 4SQRP team and members.
>>>
>>> David -NA1MH
>>>
>>>
>>>
>>> Sent from my Verizon, Samsung Galaxy smartphone
>>>
>>> --
>>> Sent from Gmail Mobile
>>
>>
>
> --
> bark less - wag more
>
>



Re: Member List

Tim N9PUZ
 

There are people who come to OzarkCon from Michigan now! Why move?

:-) Tim N9PUZ

On 2/8/2017 9:28 PM, Bill Cromwell wrcromwell@... [4sqrp] wrote:


Here ya go...

Move OzarkCon to Grayling Michigan!

73,

Bill KU8H

On 02/08/2017 09:07 PM, David Martin davemrtn@... [4sqrp] wrote:

That would be a 'historic' OzarkCon event !

How do we make it happen !!! ????

David Martin - NA1MH <https://www.qrz.com/lookup/na1mh> - Mountain
Home, Ar. -----------------------------------------
On 2/8/2017 19:41, ktalbott ktalbott@... [4sqrp] wrote:
It would be interesting to see them all at Ozarkcon!
Ken ke4rg


Sent from Samsung Mobile



-------- Original message --------
From: "Johnny Matlock jomatlock@... [4sqrp]"
<4sqrp@...>
Date: 02/08/2017 5:54 PM (GMT-05:00)
To: 4sqrp@...,davemrtn <davemrtn@...>
Subject: Re: [4sqrp] Member List


Look out SKCC here we come!!
Thanks for the info Dave
Johnny AC0BQ
On Wed, Feb 8, 2017 at 1:40 PM davemrtn davemrtn@...
<mailto:davemrtn@...> [4sqrp] <4sqrp@...
<mailto:4sqrp@...>> wrote:

WOW !!!

I see the 4SQRP member count very recently surpassed 1300.

Way to go 4SQRP team and members.

David -NA1MH



Sent from my Verizon, Samsung Galaxy smartphone

--
Sent from Gmail Mobile
--
bark less - wag more


Re: Member List

Bill Cromwell
 

Here ya go...

Move OzarkCon to Grayling Michigan!

73,

Bill KU8H

On 02/08/2017 09:07 PM, David Martin davemrtn@... [4sqrp] wrote:

That would be a 'historic' OzarkCon event !

How do we make it happen !!! ????

David Martin - NA1MH <https://www.qrz.com/lookup/na1mh> - Mountain Home, Ar. -----------------------------------------
On 2/8/2017 19:41, ktalbott ktalbott@... [4sqrp] wrote:
It would be interesting to see them all at Ozarkcon!
Ken ke4rg


Sent from Samsung Mobile



-------- Original message --------
From: "Johnny Matlock jomatlock@... [4sqrp]" <4sqrp@...>
Date: 02/08/2017 5:54 PM (GMT-05:00)
To: 4sqrp@...,davemrtn <davemrtn@...>
Subject: Re: [4sqrp] Member List


Look out SKCC here we come!!
Thanks for the info Dave
Johnny AC0BQ
On Wed, Feb 8, 2017 at 1:40 PM davemrtn davemrtn@... <mailto:davemrtn@...> [4sqrp] <4sqrp@... <mailto:4sqrp@...>> wrote:

WOW !!!

I see the 4SQRP member count very recently surpassed 1300.

Way to go 4SQRP team and members.

David -NA1MH



Sent from my Verizon, Samsung Galaxy smartphone

--
Sent from Gmail Mobile
--
bark less - wag more


Re: 43SQRP net

Paul Smith
 

Thanks for the report Charles,

I was getting some thunderstorm static as well. not sure from where but it was there

de Paul N0NBD


Sent from Outlook




From: Charles Moizeau
Sent: Thursday, February 9, 2017 2:13 AM
To: 4sqrp@...; Paul Smith
Subject: Re: 43SQRP net
 

Condx in NJ are very noisy with a major snow storm arriving here in six hours.  At 0130Z-ish I heard Wayne at 449.  Normally WA9PWP is the sig champ, but I didn't hear him.  Surprisingly, the other Paul, N0NBD, was nearly 569.


Charles, W2SH 






From: 4sqrp@... <4sqrp@...> on behalf of Paul Smith psmith61@... [4sqrp] <4sqrp@...>
Sent: Wednesday, February 8, 2017 8:57 PM
To: 4sqrp@...
Subject: [4sqrp] 43SQRP net
 
 

WOW I had a bunch of noise here tonight I did get 

WA0ITP Terry

WA8PWP Paul

WN0WWY Dale.

Thanks Terry for the relay.de Paul N0NBD


Sent from Outlook


Re: 43SQRP net

w2sh@...
 

Condx in NJ are very noisy with a major snow storm arriving here in six hours.  At 0130Z-ish I heard Wayne at 449.  Normally WA9PWP is the sig champ, but I didn't hear him.  Surprisingly, the other Paul, N0NBD, was nearly 569.


Charles, W2SH 






From: 4sqrp@... <4sqrp@...> on behalf of Paul Smith psmith61@... [4sqrp] <4sqrp@...>
Sent: Wednesday, February 8, 2017 8:57 PM
To: 4sqrp@...
Subject: [4sqrp] 43SQRP net
 
 

WOW I had a bunch of noise here tonight I did get 

WA0ITP Terry

WA8PWP Paul

WN0WWY Dale.

Thanks Terry for the relay.de Paul N0NBD


Sent from Outlook


Re: Member List

David Martin <davemrtn@...>
 

That would be a 'historic' OzarkCon event !

How do we make it happen !!!   ????

David Martin - NA1MH - Mountain Home, Ar. -----------------------------------------

On 2/8/2017 19:41, ktalbott ktalbott@... [4sqrp] wrote:
 
It would be interesting to see them all at Ozarkcon!
Ken ke4rg


Sent from Samsung Mobile



-------- Original message --------
From: "Johnny Matlock jomatlock@... [4sqrp]" <4sqrp@...>
Date: 02/08/2017 5:54 PM (GMT-05:00)
To: 4sqrp@...,davemrtn
Subject: Re: [4sqrp] Member List


 
Look out SKCC here we come!!
Thanks for the info Dave
Johnny AC0BQ 
On Wed, Feb 8, 2017 at 1:40 PM davemrtn davemrtn@... [4sqrp] <4sqrp@...> wrote:
 
WOW !!!

I see the 4SQRP member count very recently surpassed 1300.

Way to go 4SQRP team and members.

David -NA1MH



Sent from my Verizon, Samsung Galaxy smartphone
--
Sent from Gmail Mobile


43SQRP net

Paul Smith
 

WOW I had a bunch of noise here tonight I did get 

WA0ITP Terry

WA8PWP Paul

WN0WWY Dale.

Thanks Terry for the relay.de Paul N0NBD


Sent from Outlook


Re: Member List

Ken Talbott
 

It would be interesting to see them all at Ozarkcon!
Ken ke4rg


Sent from Samsung Mobile



-------- Original message --------
From: "Johnny Matlock jomatlock@... [4sqrp]" <4sqrp@...>
Date: 02/08/2017 5:54 PM (GMT-05:00)
To: 4sqrp@...,davemrtn <davemrtn@...>
Subject: Re: [4sqrp] Member List


 

Look out SKCC here we come!!
Thanks for the info Dave
Johnny AC0BQ 
On Wed, Feb 8, 2017 at 1:40 PM davemrtn davemrtn@... [4sqrp] <4sqrp@...> wrote:
 

WOW !!!

I see the 4SQRP member count very recently surpassed 1300.

Way to go 4SQRP team and members.

David -NA1MH



Sent from my Verizon, Samsung Galaxy smartphone

--
Sent from Gmail Mobile


Re: Hot IRF510

David Wilcox
 

Thank you to all the responses.  Will evaluate further and replace the IRF510.

Dave K8WPE

On Feb 8, 2017, at 6:24 PM, nw8l@... [4sqrp] <4sqrp@...> wrote:

 

Oops, the link to the ARRL note was truncated, here it is again:



Bob NW8L



---In 4sqrp@..., wrote :

Yes, I ran into the same problem, Q6 failed and was running extremely hot etc. not long after I built the kit.

At first I removed it and completed the (-) path with a piece of wire, later I replaced it to restore the polarity protection it offers.

The gate of Q6 (a MOSFET) is directly connected to the (+) input power pin. I suspect that it was damaged by static discharge, so now I'm very careful when connecting the power to the radio.

Eventually I'll lift the gate lead of Q6 and kludge in an RC ESD protection network like that seen in figure 2 of this ARRL note:


If that works out I'll have additional peace of mind, it's very dry here in NM and electrostatic discharge can be a problem.

Bob NW8L


---In 4sqrp@..., wrote :

I am finding that my reverse voltage IRF510 is running hot enough to burn my fingers, even when the BJ is switched off. I was questioning why my Jet Ski battery was running down after a few days of "just sitting on the bench" while connected to the turned off BJ.

Any suggestions?

Also the receiver oscillator transistor seems to be the temp sensitive wandering part. I sprayed lightly each part with coolant air and that part seems to move frequency the fastest and the farthest. The toroid is also temperature sensitive but less so.

Dave K8WPE

Dave K8WPE


Re: Hot IRF510

n5ib_2
 

Sounds like that may be another instance of a failed Q6. That is a clever circuit that minimized voltage drop in the supply line, but the IRF510 can be damaged by esd. When (if) you replace it, tack a 470K or a 1 Meg in parallel with a 0.01 uF cap across from gate to source. That will protect it from most esd, and will only pull a few uA from your power source.

On the temp stability.... the iron powder of the toroid core has a positive temperature coefficient. One trick you can do is replace C20 with a polystyrene capacitor. They have a negative coefficient. Don't expect to cancel the drift, but at least they'll be going in opposite directions.

N5IB


Re: Hot IRF510

Bob NW8L
 

Oops, the link to the ARRL note was truncated, here it is again:


Bob NW8L



---In 4sqrp@..., <nw8l@...> wrote :

Yes, I ran into the same problem, Q6 failed and was running extremely hot etc. not long after I built the kit.

At first I removed it and completed the (-) path with a piece of wire, later I replaced it to restore the polarity protection it offers.

The gate of Q6 (a MOSFET) is directly connected to the (+) input power pin. I suspect that it was damaged by static discharge, so now I'm very careful when connecting the power to the radio.

Eventually I'll lift the gate lead of Q6 and kludge in an RC ESD protection network like that seen in figure 2 of this ARRL note:


If that works out I'll have additional peace of mind, it's very dry here in NM and electrostatic discharge can be a problem.

Bob NW8L


---In 4sqrp@..., <djwilcox01@...> wrote :

I am finding that my reverse voltage IRF510 is running hot enough to burn my fingers, even when the BJ is switched off. I was questioning why my Jet Ski battery was running down after a few days of "just sitting on the bench" while connected to the turned off BJ.

Any suggestions?

Also the receiver oscillator transistor seems to be the temp sensitive wandering part. I sprayed lightly each part with coolant air and that part seems to move frequency the fastest and the farthest. The toroid is also temperature sensitive but less so.

Dave K8WPE

Dave K8WPE