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Re: 'Tis the season for 10m AM! class-e amp help request

PostPosted: Wed Nov 19, 2008 12:39 pm
by W5EFR
That is a Commercially sold amplifier.... But like I said, there are a lot of people using the "palomar" name when Palomar has been out of the business for a LONG time! :shock:

I think there are photos of the actual amp on this page, but for some reason, my work blocks it...
http://www.amateurlinearamplifiers.com/ ... ource=menu

Toward the bottom of the page

They made a Mosfet 450 and a Mosfet 700, but I can't find anything on the internet about them...

Re: 'Tis the season for 10m AM! class-e amp help request

PostPosted: Wed Nov 19, 2008 9:01 pm
by W5EFR
Bruce...

Here you go, it is a "commercial amp"

Palomar Mosfet 250:

Image

Palomar Mosfet 450

Image

Image

Re: 'Tis the season for 10m AM! class-e amp help request

PostPosted: Thu Nov 20, 2008 7:50 am
by kf1z
Man, they're getting away eith some long leads, and bulky layout for "10 meters".

Re: 'Tis the season for 10m AM! class-e amp help request

PostPosted: Thu Nov 20, 2008 10:15 am
by W5EFR
Agreed.

I have heard that these amps are built by 1 guy, who is currently not building them.

My question is:

By looking at the MosFet datasheets, how would one know that it will work at 30 mHz? :|

Re: 'Tis the season for 10m AM! class-e amp help request

PostPosted: Thu Nov 20, 2008 8:39 pm
by frank carcia
Layout sucks. Input leads way too long flipped over the part.
A nice 10 meter amp right out of the box. Check CTR surplus on ebay. MRI strip with a 3 stage amp using a pair of MRF150s in the final. for around $60. Just needs a few wiring changes to make the bias work right.
I have all the mods because I've modified a 3 of them down to 160. Set up for 63 mhz but work fine on 20M through 6M stock. Very well build made by ERBTECH. I was lucky to score a 1 KW module but have not modified it yet. 10 mw will drive the then to full power if you bypass the MMIC amp. If you use the mmic 30 or so dB lower drive. I drive the three stages of push pull with my HPSDR penny exciter and it sounds good. gfz

Re: 'Tis the season for 10m AM! class-e amp help request

PostPosted: Fri Nov 21, 2008 12:47 am
by W5EFR
Sounds interesting...

Must Be these?

http://cgi.ebay.com/ERBTEC-RF-AMPLIFIER ... .m20.l1116

What type of modification is needed for HF AM use?
How many watts do you get from them?

Re: 'Tis the season for 10m AM! class-e amp help request

PostPosted: Fri Nov 21, 2008 8:34 am
by frank carcia
Linear 300 watts PEP......AM linear you need to mount it on a bigger heat sink50- 75 watts carrier.
Class A it will do 100 watts of very clean signal.
works great on 6M.
MRI was used in some sort of gatyed pulse where bias is turned on then the pulse

Re: 'Tis the season for 10m AM! class-e amp help request

PostPosted: Fri Nov 21, 2008 11:30 am
by G4ZOW
As the little IRF's have come up in conversation on this thread I thought I'd post a link to one of the modules which we sell on our site.

It's heavily underated on the suggested supply voltage and optional power supplies to make it idiot proof but as an FM amp we can comfortably see 100w out right across the FM broadcast band by winding up the voltage but there'd be no headroom for poor loads etc:

http://www.broadcastwarehouse.com/bw-br ... 43/product

Click on hi-res image link for a better picture. Note our clamp to hold the little blighter down.

BTW, I agree re the excessive wiring on that Palomar amp.

I have several old Metron HF mobile 12v amp's in my collection and they are real neat compared to the above and run around 600w pep out.

I hate wires.

Phil G4ZOW

Re: 'Tis the season for 10m AM! class-e amp help request

PostPosted: Fri Nov 21, 2008 11:34 am
by G4ZOW
Forgot to state that the above runs 2 x IRF510's.

Phil G4ZOW

Re: 'Tis the season for 10m AM! class-e amp help request

PostPosted: Mon Nov 24, 2008 2:14 pm
by W5EFR
Any thoughts on the Mitsubishi RD100HHF1?

30 Mhz, 12Vdc, 100 watts output

http://www.rfparts.com/pdf_docs/RD/rd100hhf1.pdf

RF Parts lists them for $28 each...

Re: 'Tis the season for 10m AM! class-e amp help request

PostPosted: Mon Nov 24, 2008 4:58 pm
by kf1z
W5EFR wrote:Any thoughts on the Mitsubishi RD100HHF1?

30 Mhz, 12Vdc, 100 watts output

http://www.rfparts.com/pdf_docs/RD/rd100hhf1.pdf

RF Parts lists them for $28 each...


Fine for linear, or maybe Class C


Only a 50volt device....

Still would have to run at no more than about 5 volts at carrier tops for AM ....

For Class=E, really need to look for 500 volt plus devices.....

Re: 'Tis the season for 10m AM! class-e amp help request

PostPosted: Mon Nov 24, 2008 5:13 pm
by kf1z
One device I want to give a whirl with is the IXZH10N50LB

It's a 10 amp 500 volt linear RF FET made by IXYS

Ciss = 598pf
Cdss = 78pf
Crss = 8pf



Might be fun !

I ran across these on ebay for short money compared to the current Price ($30. each)

Re: 'Tis the season for 10m AM! class-e amp help request

PostPosted: Fri Jul 29, 2011 11:43 pm
by Stu
DEIC420 @ 10m has anyone tried this :?: and if so for a 1nf load did you get anything usable (5w/10w drive :?:) or are we talking the next step up to the BIG $$ (IXZ4DF18N50) :?:

Re: 'Tis the season for 10m AM! class-e amp help request

PostPosted: Wed Aug 10, 2011 10:43 am
by Diego-CX4DI
the DE475-501N44A of Microsemi cost $38 and will work properly.

73's
Diego
Cx4DI

Re: 'Tis the season for 10m AM! class-e amp help request

PostPosted: Tue Aug 16, 2011 8:00 am
by kf1z
Diego-CX4DI wrote:the DE475-501N44A of Microsemi cost $38 and will work properly.

73's
Diego
Cx4DI



This IXYS fet has 5nF input C ( Ciss) .

What driver or drive schem will drive it properly?

Thanks
Bruce
kf1z