Tuning with PowerSDR & Hardrock 50

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gerry kavanagh

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Dec 3, 2019, 8:48:00 AM12/3/19
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I realise that this is only tangential to the HL2, but am throwing it out there for some ideas, since others may be using a similar situation to me.
I use PowerSDR primarily, and have my HL2 feeding into a Hardrock50 linear, and into an Inverted L with an SCG 239 ATU at the feed point.
The SCG takes about 5w to start a tuning cycle.
When I key the Tune button on PowerSDR, even if I have Tune Drive set to 1, I still get the carrier amplified by the HR50, giving a Tune level of about 35W, which is both rude and possibly detrimental at high SWR.
I can manua

gerry kavanagh

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Dec 3, 2019, 8:49:52 AM12/3/19
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Oops... posted incomplete in error...
To continue... I can manually disable the PTT and tune at drive level 5, which gives the desired low powered signal, but this is mildly inconvenient.
So, has anyone else handled this, and if so, what was your solution?
/ Gerry

Steve Haynal

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Dec 4, 2019, 12:55:33 AM12/4/19
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Hi Gerry,

Sorry, I don't have a good answer. Is tune in PowerSDR set to use tune level or drive level? 

73,

Steve
kf7o

gerry kavanagh

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Dec 4, 2019, 4:05:18 AM12/4/19
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Tune level. It seems less granular than drive level though. I was hoping to come up with some 'one touch' mechanism but it looks like this might be difficult.
/ Gerry

Jonas Sanamon

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Dec 4, 2019, 9:10:32 AM12/4/19
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Hi Gerry,

I'm assuming that the Tune Request and EXTTR pins are active high, but i'm not sure. Perhaps Steve can verify?

Best Regards,
Jonas - SM4VEY

Den ons 4 dec. 2019 kl 12:46 skrev gerryk <ger...@gmail.com>:
Hi Jonas...
Yes, this is a good idea indeed. I am building the level inverter for the band switching soon so I will add some logic to do this also. Thanks for the suggestion.
/ Gerry

On Wed, 4 Dec 2019 at 11:35, Jonas Sanamon <san...@gmail.com> wrote:
Hi Gerry,

Wouldn't a way to not trigger the external PA during tune solve your problem?
You ought to be able to put together a simple external (daughterboard) with logic that uses the new tune request output from the HL2 together with the EXTTR so that the external amp is only triggered when the "tune request" signal is low?

EXTTR --------------|
                   (AND) ----------- relay for ext. amp
   TR ---(Invert)---|

In case I'm just totally confused, please ignore post :-)

Best Regards,
Jonas - SM4VEY

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gerryk

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Dec 4, 2019, 9:17:14 AM12/4/19
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Had a bit more of a think and it looks is if switching the amplifier to QRP mode before tuning is the right thing to do. This can be done by serial command.
/ Gerry

Jonas Sanamon

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Dec 5, 2019, 2:40:37 PM12/5/19
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Hi Gerry,

Well, perhaps for the softrock it's the simplest solution. But I think the solution I proposed would probably work as a generic solution regardless of amplifier model? At least for tuners that can tune with the power levels that the HL2 by itself can generate.
So I guess I have to hack together this for myself once I get an end plate :-)

Best Regards
Jonas - SM4VEY

Steve Haynal

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Dec 6, 2019, 12:24:36 AM12/6/19
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Hi Group,

I ordered all the parts and PCBs for the new back end plate with IO and other small boards I've been working on. Everything should arrive next week. I'll add some assembly pictures, and probably make a few small updates to the BOM. The sense of the signal will depend on whether the level shifter or mosfet output is used. For EXTTR, it is active low. The external device provide a pulled up signal and the HL2 will short it to ground via the NUD3124 when activated.




73,

Steve
kf7o

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Steve Haynal

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Dec 12, 2019, 2:03:31 AM12/12/19
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Hi Group,

I've received my order of PCBs and parts. I will kit the IO end plates and parts for the ~10 testers this weekend. Below are some pictures.

back.jpg

This is a rear view of the 40mm plate. The ACC1 connector is using a 5 position terminal block. It also supports a smaller 9 position. The ACC1 is meant for connecting to ATUs. The wires enter the terminal block from the bottom. The terminal block can also be oriented upwards if desired.


The ISO terminal block is not installed. The ones I ordered are very tall. It supports 3 position 5.08mm spacing or 5 position 2.54mm spacing. It is intended for EER/ET connections to the optoisolator.


RF3 is a SMA connector to provide feedback from a PA for PureSignal.


On the PCB, there are some vias and one trace on the outside surface. The vias are tented so they are barely noticeable.


There is some crowding around RF3 and ISO. I think it is workable, but I may do something to ease this in future revisions.


inside.jpg

This is the inside view. Not all the components are installed, but the surface mount headers are. The bottom row of the lower surface mount header is close to some filter inductors, but there is only power/gound on the bottom row.


The small board to facilitate wiring to the DB9 is soldered to the DB9 connector. The level shifter circuit can be soldered directly to this board instead of using the end plate. This board can be shortened just by clipping with some wire cutter along a dotted line with holes. The short version is for those not wanted to use the level shifter circuit on this board.


largejumper.jpg

This shows the large connector board with additional MCP23008 output and PureSignal feedback with high impedance attenuator. The SMA connector is workable but close to T3. I may move that in future revisions or flip the board so that it extends out over the N2ADR filter board.


twosmall.jpg


This shows the small PureSignal feedback board with SMA. This solders right on top of the existing connector board. It also includes the high impedance attenuator. It can be reversed as is to extend over the N2ADR filter board instead.


Also, the small MCP23008 IO expander board which connects to DB17 is shown. 


The two uses of MCP23008 IO expander are examples of how to connect to the I2C bus. Other devices can be connected to these locations such as a small microcontroller or DAC/voltage divider for voltage level specified band information.

Jonas Sanamon

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Dec 12, 2019, 3:56:13 AM12/12/19
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Hi Steve,

That looks great!  

Best Regards,
Jonas

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