VK Logger Ham Radio Forum Archive

Gday all, Finally got some time to play with the VE1ALQ amp. Rebuilt as per Darrell,s web page...no difference... Confirms Tim's observation that the MRF from UTsource are crook.....batch no 038006... The first pair of MRF 286 I got from UTsource went into a W6PQL board and worked fine. Currently my...

Hi Tim
Mine have a batch number 038006......

I will be rebuilding mine as per Darrell's instructions, when time permits......


Cheers

Phil VK4CDI

Hi Tim I built mine a la W6PQL, 50mm x 110mm x 6mm block of copper with achannel milled in so the PCB just fits between device tabs and the copper block. Whole lot is bolted to the heatsink, using 6mm x 100mm wide Al bar as spacers. Devices are bolted in, I was planning to solder them in once it was...

Hi Tim
Haven't had time to do anymore with mine, other than close up the PCB to the MRF286...no change, as per your results.
It is looking like an expensive shack warmer.......

73

Phil VK4CDI

Tim,
I am using the Sapphire Gigatrim caps as specified by Darrell.....
I have a 6mm thick copper block with a channell machined into it for the MRF's, no spacer needed for the PCB.....

Will let you know results when I play with port swapping.....

Cheers
Phil
VK4CDI

Hi Tim, I have finished mine, using the recommended components, but can't get it working.......I am using screw in 286's at the moment, I may try soldering them in later.. I can set the bias OK....1A per device. 5W drive and drain current is 8A, but only 2W out.... I will try swapping I/P ports as p...

Anyone got one of these amps? Got it working? Can't seem to get anything out of mine. Using MRF286 from UTsource......


Phil VK4CDI

Tnx for the replies....
Have ordered some from RFmicrowave.it.....
approx 6 Euro each, but min orde 30 Euro, so 5 on the way, 12Euro postage....

Cheers
Phil VK4CDI

Anyone know where I can get a couple of Johanson Sapphire Giga trim trimmers.....6-4.5pF
Part No 27273.

Cheers
Phil VK4CDI

Tim
Go onto Darrell's site and get some samples from ATC.......
I have 2 reels of 10 each 1.8 and 22 on the way...free!

Where did you get your 150W termination?

Phil VK4CDI

Hi Tim
Can't help with the caps, but did you buy a PCB from VE1?
Where did you source your MRF286's?

Cheers
Phil VK4CDI

RR Andy, Moree 73-80, spent 6 mths at Paddo first, training.....

Cheers
Phil VK4CDI

Hi Andy,
Off topic, but where in OTC? Ex Moree here.....

Phil VK4CDI

Doug VK3UM has some software, EMRCALC, specifically for EMR measuring.

Cheers
Phil VK4CDI

Good stuff Dave, I will check out that software..... Last weekend, rewelded the El pivot arm, it wasnt mechanically correct. The power supply feeding the 36V linear actuator sags badly,40V down to 22 on load, so need to fix that. I think I have found my low Tx problem! Not enough drive to the SSPA, ...

Just been through the same process. I have a TS2000 and wanted 23cm. (My transverter/IC202 combo just wasnt happening!) A 910 H with 23cm module and TCXO option works out to nearly as much as a 2000x, so I paid the extra 300 or so to get the 2000x. Plus I dont have to learn how to use a new rig, and...

And even more importantly, our 'other modes' should be 400/500, not 120W!

Phil VK4CDI

I planned to attend this year, but which one?
Think I'll hang out for the July one.
What's the best way to get there?
Fly to Tullamarine and car?
Don't seem to be flights from BNE to Latrobe?

Cheers, and hopefully see you all in July

Phil VK4CDI

Finally.......... Isolation relay causing a problem, so runnin g direct to preamp (no TX) 13dB sun noise. Moonset Sat night was like the low end of 20Mx (during sunspot low!!) several CW sigs...then PI9CAM at S6. G4CCH at -12 on JT Guess RX is FB!! Sun arvo fixed relay, 12.5dB sun noise, ready to go...

Great stuff Dave!!
Hole dug, concrete in, support pole bolted down, prop pitch refurbished, Linear actuator ordered, mounting hardware welded and painted, phew.......

Hopefully won't be too much longer...
73
Phil VK4CDI