BK Precision 4086AWG 80 MHz Arbitrary Function Generator - Page 1
Forum section: electronics / testgear

author: pienari
author_rank: Regular Contributor
timestamp: May 17, 2023, 07:08:34 am
content: I have a problem with RF output power.Have anyone modified full power freq range over 40MHz?.Full power 20v p-p 0-40MHz over 40MHz power drops to 4v p-p.I disassembled unit and i found output have an relay array what is cpu controlled.I tested add voltage to relays but it not raise to output.This maybe needs mod software?.

author: Detlev
author_rank: Regular Contributor
timestamp: May 17, 2023, 07:23:25 am
content: that's no problem, that's according to the specifications:For all models Freq 40MHz: 2mV ~ 20Vpp (open circuit) , 1mV ~ 10Vpp (50)4084, 4085, 4086 Freq > 40MHz: 2mV ~ 4Vp-p (open circuit), 1mV ~ 2Vpp (50)

author: pienari
author_rank: Regular Contributor
timestamp: May 17, 2023, 09:51:08 am
content: Yes i know it works as it should but i need more output power over 40MHz.

author: coromonadalix
author_rank: Super Contributor
timestamp: May 17, 2023, 10:17:58 am
content: Wich is normal in a way .. it is designed like this ??And hacking it wont help, if the output signal is indeed in specsYou have to add an external amplifier ....

author: pienari
author_rank: Regular Contributor
timestamp: May 17, 2023, 12:07:58 pm
content: I think software mod chould be possible solution.I havent found firmware but i havent ask it from BK.

author: coromonadalix
author_rank: Super Contributor
timestamp: May 17, 2023, 04:35:14 pm
content: Im not aware theses gen series are hackable .... not like Rigols or Siglent ones who options are hackable, but did not saw anithing related to amplitude levelsand you dont specify what amplitudes levels you need .. it wont help you get some answers ...do yourself some firmware dumps, eeprom dumps inside of it, and do reverse engineering ??and with patience maybe someone can or will help

author: TurboTom
author_rank: Super Contributor
timestamp: May 17, 2023, 04:46:30 pm
content: Why does this 500ml bottle of beer only contain half a liter? There must be a way to put one liter in, I've got to discuss this with the brewery...Sorry for my sarcasm, but a modern AWG's output stage is quite a tricky design, usually consisting of several, stacked current feedback opamps that, depending on the selected range may or may not get used (thus the array of relays). Offset mixing is often taking place via a separate DAC and passively added to the waveform signal in order not to waste signal resolution, fidelity and to introduce distortion. On these output designs, the factor limiting the output amplitude usually isn't gain-bandwidth product of the amplifier but rather slew rate at the required drive currents.Though the amplifiers obviously provide some headroom that could possibly be exploited, I'm very much in doubt that you will find any manufacturer of such gear who would support you in an attempt to do so. A dedicated power amplifier after the AWG's output is definitely the way to go.

author: mawyatt
author_rank: Super Contributor
timestamp: May 17, 2023, 04:57:08 pm
content: Quote from: TurboTom on May 17, 2023, 04:46:30 pmExactlyBest,

author: pienari
author_rank: Regular Contributor
timestamp: May 17, 2023, 06:25:27 pm
content: Well.. i havent found any info from web , maybe BK is so rare.

author: mawyatt
author_rank: Super Contributor
timestamp: May 17, 2023, 07:15:20 pm
content: Quote from: pienari on May 17, 2023, 06:25:27 pmMinicircuits has a large array of various RF/MW amplifiers.https://www.minicircuits.com/WebStore/Amplifiers.htmlYou can look around here for AWG Buffer Amplifiers that are a specific for a given voltage, current, power and frequency range.There's no Swiss Army Knife Amplifier that covers all bases for, frequency, power, voltage, current, linearity, and noise we're aware of, if you find one please enlighten usBest,