Search results

Hi Shock, OK, so we've come full circle regarding operating characteristics at 12V. Let's just stick with 12V for now. Is there any devices out there which at 12V can offer superior performance to that of the 2979, taking not just IMD but RF output and cost into the equation? I can...

Hi Shock, The idea is to redesign a new board to hold 16 devices. I'm aware of more modern ferrite cores so may find something superior to the early type 43 which I believe was considered best for 2-30MHz. Interesting your comments re 28V devices. I may fire one up with say 14V and see...

Shockwave & Co, You make some very valid points. Airpax produce the circuit breaker in the Metron. I would propose not just a heatsink to sit under 16 devices but a copper spreader and some forced air cooling with tunnel design chassis with inlet & outlet like our FM TX's & PA's...

...not copiers! I have a one-off job up for grabs for a negotiable fee. Here's the schematic of one of my Metron/Transword Communications amp's: I would like this circuit modified to incorporate 16 X 2SC2879's. So that requires new input splitter, output combiner and hopefully a superior...

Sorry for any confusion. My fault for not writing up the subject line correctly. I thought mobile voltage of 13.8 was nearer 14 than 12, however I hear where you're coming from. OK, let's try this again. From a '14 volt' rail do you think you'd see more out of say 16 X 2979's as...

I stated 14V!

I believe this is rated at 700W. Does anyone know of anyone working on a higher powered FET amp? Thanks.

I'm sure Kenwood, Yaesu etc really won't be too interested in selling individual parts from their circuit boards. The cores above are from a Jap company: TOMITA ELECTRIC CO., LTD. Ferrite Cores, Electronic Components. however they have ceased production as I've stated above. What do you...

Are there any manufacturers left that produce monster cores like these beauty's: I'm trying to convert the pdf data sheet of this Japanese company into a jpg but not having much luck. Will try later. The company have ceased producing these cores. Dishtronix purchased the last 500...

I don't have any old broadcast transmitters lying around on your side of the pond. I do have a solid state kilowatt unit that's waiting for a new home. I have a friend who buys up AM stations in fire sales. If I hear of something I'll pm you. Unit 148

You're right of course. Interesting as you say on the big boxes. An alarm lights comes on and one can hot swap a 1kw+ module without the listener even noticing. I think Nautel have done away with the modulator these days all up there in class-E or whatever and so very efficient: Their...

BTW, that latter photo is from a Harris 50kw Am TX and is a photo from one of the 50 PA modules in the WABC transmitter. Phil Unit 148 London, England

Hi Toll, I'm not so sure. They work just fine at 1MHz :biggrin: I manufacture and sell this stuff for a living although these are not from my products but from two US companies: 4-pill 8-pill (1500W) Phil Unit 148 London, England

Surely you'd prefer to have a Metron in the trunk? So much neater back in the 80's. Who needs all that untidy wiring anyway. Here's one of my two. I still have one brand new in it's 20year+ old box. Unit 148

Jeff, Now you're going back in time indeed showing that solid state Varmint. I dealt with the designer Abe Brewer (RIP) out of Porter, OK in the 70's. I imported Abe's first SSL600 into the UK, drove it with an early Yaesu FT301S (10w version of the 100W 301D) and it rocked driving an...

Thanks guys. That's answered my question. Phil Unit 148

I should of said 8 transistors in my amp. :blink: Phil

If you have 16 matched output transistors in a push pull PA can you optimise bias with a single pot as in my amp here; or is there an advantage in being able to set the bias to each pair of devices? Phil Unit 148

Glad I came across your post as I'm seriously considering buying this radio for use strictly mobile. What other accessories are you using with this radio, mic, amp, antenna? Unit 148 11m G4ZOW All other bands

I think that works out about right as this device has around 10dB gain so 12 in for 120 out in an ideal world. Therefore unless one has a driver I cannot drive 16 pills from a typical ham HF transceiver with 100W output. I really need a 200W rig like the Kenwood 480 which runs 200W output and...