开云体育

The IRFz24 might be made to work well at 7mhz,?but is not a drop in replacement on the uBitx.
Be prepared to give it significantly more drive, especially if you hope to run it at 30mhz.

Total gate charge of the IRF510 is 8.3nC
Total gate charge of the IRFz24 is 25nC

The IRF510 is hard to beat as a cheap NFET for an HF amp.

Jerry, KE7ER

Gorgeous. Very clean soldering. And no flux leftovers.

I used to design my own circuit boards with ExpressPCB software and etch them
with toner transfer. Not as good as a board house, but I could have
an idea in the morning, and a board in my hands the same afternoon.

- Jerry KF6VB

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Jack, W8TEE

It is worth noting that Hans SUmmers of Qrp Labs will use the Vishay IRF510s and none other. He did a lot of tests before he came to that conclusion.
If you go to him for spare parts for a Qrp Labs kit - that is what he will sell you.? I don't believe he offers them as a? general on line sale part because of his restock costs.?

There? is a huge flag that the items shown are not even in a real photo. When you click on the RH image what comes up is a 3d impression with non real codes on it. So what the hell - do they even have them to photograph. I hate it when semi conductor vendors do this. If it is an Ebay seller? I don't want to know as likely he is selling product he does not have in stock? but he can get at the local bazaar .? That is forbidden in Ebay vendor policy, he can be struck off Ebay for doing that if you report it.

IRFz24 is a nice RF subs for the IRF510.? It has been used to produce 45 W PEP in 7 Mhz ccts? in ARRL supervised tests.? ?They are around 80c each from Tier one suppliers. Also they will come out of the same tube in general so are likely to be closer matched. Thermally they are about 30 percent better. Don' t go past the STP60N Mosfet either as used in the Texas topper RF amp. it has Cin intermediate between the IRF510 an the? z24 as mentioned above.? What world of possibilities to choose from !!!

TE. Fidler?

Hello,

After several week-ends of soldering ding and fun to add the SMD components, my Ubitx is almost finished. Only the PCB was made in China.
I still have a few things to add (Quartz to test, 2nd Arduino, choice of the final transformer and transistors of the PA, and one regulator).
Project made with Kicad from a UBITX V6 schematic? with additional improvements (Micro amplifier, separate or no Nextion Alim, AGC, SWR, 2nd arduino, additional relay, options on 45MHZ filter, options on PA Power, noise reducer, etc).
I didn’t made any test a this point
And so it deserved a beautiful LOGO
cdt

I have been doing the remote control thing for digital modes lately using a little Raspberry Pi-zero W which has built in WiFi. The intention was to act as a local hotspot when out in the boonies so I can use an inexpensive tablet to control it, but I have even left it connected at home and linked to it while waiting for a car repair many miles away and made contacts on FT8 and PSK31. The Pi-zero is a bit limited in processing capability, but cheap and the size of a stick of gum, so it was good for the lightweight portable application I intended. If size and weight (and cost) are not factors, better results could probably be had with one of the bigger brothers like the Pi-4.

=Vic=

Reed, it would be nice from you to add such a functionality.

I know most Hams want to be free to decide by themselves to transmit or not because they are disciplined and they will never transmit on non authorized frequencies.
But some countries are more strict such as Japan and Thailand. Thailand will not authorize the import of a rig which can transmit outside of the Thai Hambands (?and they have a short lis of authorized transceivers (.
You can see the Icom IC-7300 in that list. With the IC-7300 you can enter "band edges" with a menu and you can choose one of the two following operating modes of the transceiver : 1. Beep when out of a hamband or 2. Beep and forbid transmission when out of a hamband". I think this could be a nice way to modify the source code as it would leave to the Ham the choice to have a signal like now when out of band, which most hams will prefer or prohibit the transmission, which some countries require.

I would appreciate a modification to your 1.5.1 because I am very much attracted by the iBitx, which reminds me of the first gear I built some 60 years ago, with vaccum tubes, Hi... but I shall order one only if I can have this out of band prohibition set.

73 - Pierre - FK8IH

John,

The Vishay's (and the IR parts before them) work fine in spite of the fact that they were not designed for use at RF.
Many amateurs have built linear amps with them, and I applaud that.
Cost on Mouser is $0.80 single piece, $0.30 if you buy a reel.

There are many IRF510 clones out there that simply don't work at RF due to high gate capacitance.
The assumption made is that they are being used for low frequency switching tasks.

Buy a couple hundred IRF510's of unknown manufacture for a budget price
and I've a hunch that a total of zero will screen for good RF performance.
Good luck.



Jerry, KE7ER

Should have been RD15HVF1 lol? strange it doesn't let me edit my post.

On Mon, Apr 12, 2021 at 01:25 PM, Bob Lunsford wrote:

At $2.95 for ten, it's worth experimenting with them.

?

Bob — KK5R

For that price its worth buying a couple hundred, screen them for RF performance, offer the good ones to the group and sell the junk on e-bay lol. I wish I had the time, I would do it. Retirement can not come fast enough lol, couple more years.

John

On Mon, Apr 12, 2021 at 01:17 PM, Jerry Gaffke wrote:

The ebay/aliexpress IRF510's are questionable.
Some work fine as low speed FET switches as the IRF510 was originally designed for,
but operation in a 30mhz linear amp not so much.

And what would be wrong with buying parts that are working as original intended? Just because we hams are used to using parts outside of their spec doesn't mean that parts that work inside their original specifications are junk. If one wants well performing RF FETs one needs to buy them. The RD15VH1 is such a beast that is a mass produced FET that has been screened for reliable RF performance. I used to work for a company that made RF generators for the semiconductor industry. We used switching FET's for 13.5, 27.12 and 40.68 Mhz we bought from APT and Motorola. Those were of the shelf parts but screened at the manufacturer or at the incoming inspection for RF performance. The actual usable return out of a production batch was like 45%, the rest was not usable in RF applications and were used for switching power supplies.
So if I would use IRF510s to replace the ones I have, I would buy 50 of the cheap ones, make a small test fixture of a single transistor amp with the possibility to clamp the transistor in place instead solder and then screen them for performance. That would also give the opportunity to create matched pairs.
There are ample of projects the non performers can be used in from relay switches to power supplies. Most likely though, If mine ever die I will buy RD15VH1's and replace the 510s with real RF FETs. I.M.O. the better performance is worth the extra cost

John

Saw that fellow poster Jack W8TEE was on that list too. I don't normally sign up but will for this virtual event.

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73
Dave

Best to ask MPJA.? If you need a particular manufacturer, it's better than that to order from a Tier 1 disti who WILL give you your manufacturer of choice.
IIRC, International Rectifier introduced the IRF-510 (ya know, IRF = International Rectifier FET....) and these could be surplus from them, which should make them good at RF.

Or they could be cheap Chinese knockoffs like the rest of the fleabay and Alibaba gaaah-baghe.

For $0.40 each, they may be worth taking a chance if you have a low-speed application in reserve,

73
Jim N6OTQ

Symptoms match having a pressure point on the touchscreen.?
Make sure nothing is pressing on the glass.

Talk: An Evening with Bob Heil K9EID

I used my v6 about 2 times and now the screen is unresponsive to input. Can get into calibration page but again won’t accept touch screen inputs. Can’t tune with encoder either. Have tried reflashing firmware also. Would think was touchscreen is defective but why no frequency change when rotate the dial either? Any help? Anyone else experience this?

Does anyone know if these are VIshay parts?

I would tend to buy IRF510's from Mouser or Digikey.
MPJA may be ok, but there is no indication of who the manufacturer is.

The ebay/aliexpress IRF510's are questionable.
Some work fine as low speed FET switches as the IRF510 was originally designed for,
but operation in a 30mhz linear amp not so much.

Jerry, KE7ER