and possibly a funeral plan lodged. 73 Pete GM4BYF On 02/08/2022 15:14, Neil Smith G4DBN wrote:

Gyroklystron or other gyrotron variant perhaps, using heavily overmoded cavities? Getting the required magnetic field intensity is hard though. Possible to do just over 1 T using big rare earth magnet

A TWTA for 122 GHz (Lambda of 2.4 mm) seems a geometrically difficult project. Having in hand a commercially made prototype of a 5 W TWTA for 10GHz, I cannot imagine the tedium of getting something DI

Has anyone here tried making their own amplifiers for these bands yet? A TWT amp sounds like it'd be fun to make I know sage has some on their catalogue, but it doesn't sound fun or cheap

My plot of Vt v Frequency for TRA_120_045.

Thanks for the additional data points Mike and David, My intention is to use the Icntl line set point to give a similar Vt value at both 122 & 134 G so the loop filter values will be similar and in th

Thanks, but I'm looking for the III-V compound, SiGe, diode and transistor data; I think that's just pure Ge? I guess I should just ask the fab (IHP); I was wondering if someone else already had.

Mike, This document suggests voltages of 1 volt or more. See figures on page 4. The curves also seem highly dependent on the geometry. https://www.researchgate.net/profile/Mirko-Scholz/publication/289

BTW, I wish I knew the I-V curves for a Silicon Germanium ESD diode (and also the transistors as used in the Gilbert cell diff amps)... I assume the they are somewhere between the 0.7v Si and 0.3v Ge

Hi Paul... You asked: > is there a missing scale for the gold line ? No, the same number scale for both curves, but the vertical units differ. The two curve plot was collected with the high gain tunin

Hi mike This project has inspired so many to play above 10 Ghz Re your line (if I bought 500 chips, 4 to 5 parts might not cover the range of 120 to 134) I assume the figure of 500 was not the quantit

Hi Mike, Interesting results, I've got a 2 transceivers now running with TRA120_045 chips using a newer version of my Dubus 2020 TRX with ADF41513, 80 MHz VCTCXO, etc), I did some checks tonight compa

Hi Mike Thank you for the two drawings is there a missing scale for the gold line ? Also did you mount the chip to a PCB for testing ? Regards Paul

Although, it might be better to run Ictl at 3.0v or VCC, where the tuning slope is ~3.6 GHz/V (as opposed to Ictl = VCC/2, where slope is ~ 6GHz/V) ... might be less phase noise.

Data attached

Hi, Andrew, I was able to run Vt up to 5.0v by using a PLL VPP of 5.06v and a TRX VCC of 3.45v (just below max spec). Silicon Labs told me that they have only screened a sample of 160 chips and don't

Barry thank you for the explanation Paul

Paul many RAs in the south of the UK use 144.0 for historical reasons. I often use a SDR for my IF and some of these generate a sproggy at 144.0 which is possibly due to a harmonic of the USB clock. H

High Barry Why is 144.000 MHz IF being used as a lot of 2 Mt equipment will not tune below 144 also there is a strong signal at 144.000 that could desensitise a 144.000 MHz IF when on top of a hill So

John as 134.400 is already established in the UK, it seems logical for us to set the VK3 synth to use Tx/Rx = 134.400 and LO = 134.256 (= 144.0 MHz IF). Personally, I would still use a 144.4MHz IF, fo