alternative for MRF237

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BLF278 unlimited
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alternative for MRF237

Post by BLF278 unlimited » Tue Jun 04, 2019 6:39 pm

hi there

since im in hf transmitter building specialy in UKW transmitters im wondering if there are alternatives for the old motorola hf transistors.
I heard many guys asking about a replacement for MRF237 since they got extremely pricey but the answer was always about buying an cheaper MRF 237 from somewhere else.
If i would just build up a single transmitter i could handle those costs but there are many circuits out there, wnting for me to build them and all of those based on this rare transistors.
Also one of the main reasons is, that i ordered some fake ones already.
So yeah maby some of you might know some cool alternatives to the common stuff or maby a list with good hf transistors.

thanks :smoke

Albert H
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Re: alternative for MRF237

Post by Albert H » Wed Jun 05, 2019 12:21 am

BFQ43 was a great replacement for the '237. Also the SD1143 was great for up to around 10 Watts.

These days it's all about the FETs. Mitsubishi make their RD series FETs that are really cheap and have loads of gain. I found that I could get about 10 Watts out of the RD15 device for around 120mW drive - this does away with at least one stage in a rig!
"Why is my rig humming?"
"Because it doesn't know the words!"
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teckniqs
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Re: alternative for MRF237

Post by teckniqs » Wed Jun 05, 2019 8:47 am

A few more...

SD1127, NTE341, M9859, 2SC1947, BLY35, PT31961

radium98
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Re: alternative for MRF237

Post by radium98 » Wed Jun 05, 2019 8:31 pm

that i ordered some fake ones already.

does they work and how much rf output you get except the heat only

Albert H
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Re: alternative for MRF237

Post by Albert H » Thu Jun 06, 2019 3:14 am

The SD1127 was a superb transistor. Widely used in VHF handhelds, it could do a bit more power than the '237 and had slightly higher gain. I used to get them for 45p each!
"Why is my rig humming?"
"Because it doesn't know the words!"
;)

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Re: alternative for MRF237

Post by BLF278 unlimited » Fri Jun 07, 2019 5:40 pm

thx for the reps

well i never gave any attention to FETs in HF or even VHF i only built an 4meg morse transmitter with the good old IRF510 when i started

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