Automatic Tuning Unit

Bruce - KL7JDR

Does the Flex 6000 series Automatic Tuning Unit work in the Receive mode ? 73's , Bruce - KL7JDR

George KF2T

Yes, it does. Currently only ANT 1 is supported for TX, therefore ATU, also.

W5XZ - dan

also, the ATU does not seem to tune on CW; if you switch to SSB, it WILL tune, and seems to stay tuned when you switch back to CW...known bug in xx.17 i think..

Tim - W4TME

This is a great conversation that's separate from the main topic, so I created a new "Report a Problem" topic to continue the discussion. Please reference the new topic here: ATU does not tune in CW mode

Carl/K5HK

ATU tunes fine in CW if the Tune button is selected prior to hitting atu but tune must be manually turned off after tuning. Carl/K5HK

Steve-N5AC

The ATU is located on the PA board in the radio and, when enabled, is inline with either ANT1 or ANT2 (depending on which antenna was used for tuning). The transmitter is required to initiate the tuning algorithm in the ATU. Once the ATU has been tuned and it has been selected (ensure that the tune was successful and the ATU is not in bypass), it will also be in line with the receiver for any slices or panadapters connected to the antenna that the tune was initiated on. So the ATU does work for receive also, but only for the antenna selected when the tune was initiated. Steve

W5XZ - dan

so, under ...17 software, 'tune' should be backed off to ?? 10 ?? i HATE hot switching good relays, dude...

Steve-N5AC

For the ATU, we reduce the power out of the PA down to around 10W (sometimes lower). This is a low power level and we've had no issues related to switching antennas at this power level. Steve

W5XZ - dan

under xx.17 software, i BETTER turn TX drive down from 100%, huh ?? NOT default....

KB5XE

Steve, my 6700 with v.0.15.13 does not tune on 20M. Always reverts back to by-pass. Problem reported or just me. Owen KB5XE

Steve-N5AC

The tuner measures the SWR before and after a tune and makes decisions about the right final setting. If you have a 1.1 SWR before the tune and a 1.2 after because switching in any additional components yields a worse match, it will revert back to bypass after the tune to give you the best SWR. Do you think this is what is happening or do you have a poor match on 20m? Steve

Reggie-k6xr

I have two radios and auto tuners that tune my antenna 3.5 to 52mhz 1.1. My flex 6500 will not tune anywhere 3 of the bands. so I am using a ldg for tuner.

W4EG

Check your antenna... You have a high SWR... and the ATU will not tune that frequency. I seen this on160 meter... however, when I go to higher frequency. It works like peanut butter and jelly. SWEET!

Grump

The Flex Auto antenna tuner. Is it a roller inductor and plate capacitor construction driven by stepper motor or is it lumped constants?

VE7ATJ_Don

Given the relay sounds heard when it is engaged to find a 'solution', I would suspect the latter. I suspect it is very similar in design to the ATU's found in most transceivers these days.

Gord-VA7GP

https://community.flexradio.com/discussion/comment/20608924#Comment_20608924

It is lumped-components.

Same as my 1992 TS-850 from 30+ years ago... these built-in tuners have limited volume to work with, and toroids keep the fields tight (without coupling to everything). You get a functional tuner, but with limited range, limited power.

John KB4DU

The internal tuners in almost all rigs are lumped components due to size limitations. This also limits the range to about 3:1.

Mike-VA3MW

All HF radio internal tuners are designed to extend the range of an already resonant antenna, or about 3:1. There are exceptions, but it really depends on the antennas reactance.

It is correct called an Antenna Matching Unit.

External ATU's can cover a broader range.