Topics

IRF510 #alignment

Andrew Lenton
 

Hi I have just changed my IRF510s’ after I put too much drive into the 10 Watt amp, my fault, on replacement, the amp was very unstable and had very low gain, it turned out by IRF510 were counterfeit, some audio FET of unknown origin just stamped to say IFR510; so only buy form a known good supplier, they are only 60p from RS. Has anyone else had this issue? Unless you have a good de-soldering equipment replacing the transitors more the 3 times can damage the PCB, so put the whole kit at risk of being scrap!

 

73

 

Andrew

 

PS I have a bag of 8 in the bin now!

 

Ryan Flowers
 

Oh yes, been there!


It was not fun! Lots of blown counterfeits for sure. 

On Tue, May 26, 2020, 12:39 AM Andrew Lenton <a@...> wrote:

Hi I have just changed my IRF510s’ after I put too much drive into the 10 Watt amp, my fault, on replacement, the amp was very unstable and had very low gain, it turned out by IRF510 were counterfeit, some audio FET of unknown origin just stamped to say IFR510; so only buy form a known good supplier, they are only 60p from RS. Has anyone else had this issue? Unless you have a good de-soldering equipment replacing the transitors more the 3 times can damage the PCB, so put the whole kit at risk of being scrap!

 

73

 

Andrew

 

PS I have a bag of 8 in the bin now!

 


--
Ryan Flowers - W7RLF
MiscDotGeek - QRP and More

George Korper
 

I had similar problem, Order from Digikey or Mouser, in my case Digikey. 
I went round and round until I got Vishay IFR 510's. I received inferior Mosfets
that do not work for RF, just for switching from Amazon.

On Tue, May 26, 2020 at 3:52 AM Ryan Flowers <geocrasher@...> wrote:
Oh yes, been there!


It was not fun! Lots of blown counterfeits for sure. 

On Tue, May 26, 2020, 12:39 AM Andrew Lenton <a@...> wrote:

Hi I have just changed my IRF510s’ after I put too much drive into the 10 Watt amp, my fault, on replacement, the amp was very unstable and had very low gain, it turned out by IRF510 were counterfeit, some audio FET of unknown origin just stamped to say IFR510; so only buy form a known good supplier, they are only 60p from RS. Has anyone else had this issue? Unless you have a good de-soldering equipment replacing the transitors more the 3 times can damage the PCB, so put the whole kit at risk of being scrap!

 

73

 

Andrew

 

PS I have a bag of 8 in the bin now!

 


--
Ryan Flowers - W7RLF
MiscDotGeek - QRP and More

George Korper
 

BTW, now I replace the traces with wire instead of scrapping the board. 
Just follow the schematic and the PCB trace layout and wire direct between components. 


On Tue, May 26, 2020 at 6:00 AM George Korper via groups.io <georgekorper=gmail.com@groups.io> wrote:
I had similar problem, Order from Digikey or Mouser, in my case Digikey. 
I went round and round until I got Vishay IFR 510's. I received inferior Mosfets
that do not work for RF, just for switching from Amazon.

On Tue, May 26, 2020 at 3:52 AM Ryan Flowers <geocrasher@...> wrote:
Oh yes, been there!


It was not fun! Lots of blown counterfeits for sure. 

On Tue, May 26, 2020, 12:39 AM Andrew Lenton <a@...> wrote:

Hi I have just changed my IRF510s’ after I put too much drive into the 10 Watt amp, my fault, on replacement, the amp was very unstable and had very low gain, it turned out by IRF510 were counterfeit, some audio FET of unknown origin just stamped to say IFR510; so only buy form a known good supplier, they are only 60p from RS. Has anyone else had this issue? Unless you have a good de-soldering equipment replacing the transitors more the 3 times can damage the PCB, so put the whole kit at risk of being scrap!

 

73

 

Andrew

 

PS I have a bag of 8 in the bin now!

 


--
Ryan Flowers - W7RLF
MiscDotGeek - QRP and More

fred.g3srf@...
 

Sorry Grorge, have a look at the data sheet by Vishay from the DigiKey site. The IRF510 is designed for switching. There is no mention in the data sheet for use for RF amplifiers.

George Korper
 

The data sheet you are reading is correct. Vishay policy is not to endorse use of their product for amateur radio or medical applications. Nonetheless this is the source of the IRF 510's that come with the kit and they work exactly as supplied in the kit. 
i ordered 24, enough for 12 amps and they all work exactly the same as in the QRP Lab kit. 

On Tue, May 26, 2020 at 6:44 AM <fred.g3srf@...> wrote:
Sorry Grorge, have a look at the data sheet by Vishay from the DigiKey site. The IRF510 is designed for switching. There is no mention in the data sheet for use for RF amplifiers.

H.-W. Höfermann
 

Am 26.05.2020 um 12:44 schrieb fred.g3srf@...:
Sorry Grorge, have a look at the data sheet by Vishay from the DigiKey site. The IRF510 is designed for switching. There is no mention in the data sheet for use for RF amplifiers.

The IRF510 ARE switching devices, but are used by numerous amateurs (and probably pro's as well) as RF FETs, because it works, if handled properly. This is the reason that even that cheap devices are faked by unscrupulous people.73

Hannes


Virenfrei. www.avast.com

ajparent1/KB1GMX
 

Removing the IRF510s...

Just cut the leads at the body and using fine too like tweezer
heat the reaming pain and extract it.  THen heat the solder
in the hole and using intertia slap the board down against a
Rag or paper to catch the solder that will keep going.

IF you hit the amp hard enough to fry the IRF510s are
the BS170s still alive?  The 10W linear amp is a two
stage amp.

Allison
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ajparent1/KB1GMX
 

While the IRF510 was designed for switching it has a fairly decent
linear region of about 3V in the gate and 3-5A on the drain before
saturation.  IT only works well as a switch when the gate is drive
with more than 6V.  The difference between switch and linear for
most MOSFETS and bipolar transistors is linear vs saturated use.

The liability statement is fun to read but largely nothing to do with
the actual functionality of the device.  The datasheets I have
only lists medical and life critical use as outside their liability
I've not seen one that lists ham radio use in that context
and I include the Vishay data sheet.

I also threw in the IRF510 Intersil  and Vishay data sheets
figure 7(Intersil)  and the similar curves figure 3 in the Visahy data
is why we like it as RF amp.  They have a gain or 1-2 Siemens,
so one volt of Gate voltage change results in 1 to 2 amps of drain
current change.  That represents a lot of power gain.

Allison
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ajparent1/KB1GMX
 

George,

There is no mention of RF use for the following....
74ACT00
FST3253
IRF510
2n3904
BS170
SI5351
 and a very long and non-exclusive list of others.

That has little to do with their usefulness though for some cases it means the
engineer/designer has to develop his or her own data set for the device in its
intended use.  There is no permitted nor prohibited use other than suggested.

Allison
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Andy Brilleaux [O.B.E. pending] <punkbiscuit@...>
 

Yeah, white spot, and red spot transistors were not specified for RF back in the day.

Didn't stop amateurs from using them on top band.

What a stupid comment.

Andy Brilleaux [O.B.E. pending] <punkbiscuit@...>
 

ajparent1/KB1GMX
 

Andy,

I use one of the OZ1PIF modules for 220W on 6M.  Works well.
Its fairly robust at 28V.  Full output with 5-6W drive.

Also my main amp for QRP boost is the WA1EbY design from 
March 1999 QST, built mine around 2006 and its been running since.
FOr 4W in(has internal attenutaor) I get 55W on 40 and 20 and
37W at 10M.  Good enough.  I run mine at 26V as that seems to
be a enough to get power and still not make it fragile to SWR or
other faults.  The actual max drive without attenuator is under 2W.

What kills those amp in a moment is too much RF drive.
a few watts is more than enough.   IT actually doesn't take
much to punch holes in the gates (20V peak is enough!).

Allison
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Andy Brilleaux [O.B.E. pending] <punkbiscuit@...>
 

On Tue, May 26, 2020 at 08:45 PM, ajparent1/KB1GMX wrote:

I use one of the OZ1PIF modules for 220W on 6M.  Works well.
Its fairly robust at 28V.
But.. but... it can't be true.
IRF510's can't make RF.
I read it on a newsgroup ;-)

Gwen Patton
 

How about using TV scan tubes in HF final amp stages? Somehow, I think I remember THAT being done, too... ;)

-=-=-=-=-=-=-=-=-
73,
Gwen, NG3P


On Tue, May 26, 2020 at 3:50 PM Andy Brilleaux [O.B.E. pending] via groups.io <punkbiscuit=googlemail.com@groups.io> wrote:
On Tue, May 26, 2020 at 08:45 PM, ajparent1/KB1GMX wrote:

I use one of the OZ1PIF modules for 220W on 6M.  Works well.
Its fairly robust at 28V.
But.. but... it can't be true.
IRF510's can't make RF.
I read it on a newsgroup ;-)

Dave VE3LHO
 

On Tue, May 26, 2020 at 12:50 PM, Andy Brilleaux [O.B.E. pending] wrote:
On Tue, May 26, 2020 at 08:45 PM, ajparent1/KB1GMX wrote:

I use one of the OZ1PIF modules for 220W on 6M.  Works well.
Its fairly robust at 28V.
But.. but... it can't be true.
IRF510's can't make RF.
I read it on a newsgroup ;-)

Andy what exactly are you going on about?

ajparent1/KB1GMX
 

Dave,

Lets call it fake news.  Actually its more correctly, opinion,
and I've seen it posted by people that took IRF510s ( by name
not actual source, soem were literally some random mosfet)
and could not make them work.  However the history of using
them for RF power is a bit over 20 years old and (1999 article)
and several for years before that.  The IRF510 is a rather old
part.

The other scan tube aka sweep tubes (on this side of the pond)
is also old history that started with 807s and other look alike tubes
like 1625s where people said 4 of them in parallel would not do
1KW input SSB, and they did with about 600W out.  Later Color
TV sweep tubes were widely used for that.  A pair of them on 11M 
was an industry the FCC could not even slow down as it was so
easy to do.  It all running tube at peak powers well above spec
started with the 6V6 and 6L6...

So we make fun of that and the people who claim "it just can't be done"
and "it don't work for me".  But hey, the history of using them and
making power predates most newsgroups by easy 20 years for
the MOSFETS and easy 50+ for the sweep tubes.

It is the one beauty of being old, seen it all, know the fakes.
That's my story and I'm stickin to it.

Allison
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ohwenzelph
 

On Tue, May 26, 2020 at 12:45 PM, ajparent1/KB1GMX wrote
Also my main amp for QRP boost is the WA1EbY design from 
March 1999 QST
WA EBY (makes it easier to look up)

ajparent1/KB1GMX
 

I have to put all the keys back in the right disorder.  :)

However it is in the files area... for years.

Allison
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Dave VE3LHO
 

I understand what you are saying it just doesn't apply in this thread. As far as I can see no one has said that IRF510s don't work at RF.

Read the thread of messages in order and consider each in context of the previous ones.

Specifically, a comment was made (I assume in an offhand way) that some, supposed IRF510, MOSFETs sourced from Amazon weren't good for RF only for switching. Note that nothing was said about real IRF510s not working for RF.

A response was made that was addressed to the author of the previous mentioned post and pointed out that Vishay only claimed the IRF510 was good for switching, not for RF, in their data sheet . From which I take in context that "only being good for switching" isn't enough to disqualify a MOSFET from use at RF. It most certainly is *not* a statement that IRF510s aren't good foir RF. It is only a statement about what Vishay say in their datasheet, which I think we can all agree on. If someone seriously thinks that post actually says that IRF510 don't work for RF please explain it to me.

I think folks are connecting dots that don't exist and as a result we are getting some interesting enough posts but also some ... stupid comments.

FWIW my first rig was a Swan 500C with 2 6LQ6s so I'm well familiar with the use of off label components. And their limitations :-)