External transverter with HL2

[Charlie Rubenstein]

Hi, 

I have a 432 DEMI transverter I have tried to use with my HL2 and Thetis v.10.3.5 (Beta1).

I have tested this transverter with my Flex 6600, and it works very well. 

I have configured the transverter form in Thetis with the LO and range, and have RX gain set to 0. Unfortunately, it seems rather deaf on the HL2.  On HF, the HL2 is normally even hotter RX than the Flex, but it doesn't seem to hear very well with the transverter. 

Also, on TX, I am using the low power TX output from the HL2 but am only getting 15W from the transverter, which on the Flex (transmitting at 0dBm) gives almost 40 watts. According to the wiki, I thought the HL2 puts out up to 15dBm from that port. (I have no way of measuring that small output).

I assume this is operator error in the setup. What am I doing wrong?

Thanks,

de Charlie KB8CR

[Mike Lewis]

I use one of my HL2 with transverters and it works great.  When you say RX Gain I assume you are referring to VAC RX Gain?    You may need to turn up AGC Gain instead.  

 

Sounds like you are using Split IF configuration. You should disable the PA.   Are you using the optional IO Board?   If not then Xvtr RXIF should be connected to your ANT jack. 

 

If using the IO board, I use the Aux RF jack which requires setting Register 11 correctly.    In Thetis this can be tricky and ways to do this have been documented in this forum by me and others.  I modified the example firmware to force the right choice on VHF bands. I suggest you test with SparkSDR or Quisk which are simpler to set this inut selection correctly.  In SparkSDR it is called IO Board RX mode, set to 1, or 2 if using PS.  In Quisk it is IO Board Rx input.  For both apps these are global, not per band.  Thetis can be made to work per band but is tricky as mentioned.

 

 

 

 

Transmit:

 

You should disable the PA.   For TX in Thetis you need to ensure your PA Settings are turned up as needed for VHF bands.

 

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[Charlie Rubenstein]

Hi Mike:

I am not using the Optional IO board.  Yes, I have a split IF on the transverter. I have RF3 dedicated RX port connected to the header jumper, but have also tried using the antenna port. I do have the PA disabled. 

When I referred to the RX gain setting, I was speaking of the setting in the Xvrtr setup form:

On TX, perhaps these settings are why I'm not getting full output. I have VHF0 set to 38.8 instead of 100 like your example.

Do I need to set the bottom slider setting?

Thanks,

Charlie KB8CR

[Charlie Rubenstein]

P.S.:  I changed the PA Gain to 100.0 for VHF0, and I still get only 15W out of the transverter.

Charlie KB8CR

On Mon, May 13, 2024 at 1:11 PM Mike Lewis <k7...@hotmail.com> wrote:

[Mike Lewis]

Yes, you need to bump up the VHFx PA gain.  38 is very low.  100 should give you close to the expected 14dBm or so.  

 

I believe the watts check box only affect the labeling on the slider, can be what every you like.  I never pay attention to it really.  I set up the attenuating the TX side for worst case and any slider movement only reduce the drive from there.  I never trust the software to reliably limit the drive, a database error on update or changing SDR apps may not know (initially) about such software limits).

 

For the RX issue.  If you put your HF antenna on ANT or RF3 so you hear OK then?  If so, your Xvtr RX IF level out may be low.  Easy to tell, put the Xvtr RF output on another HF rig and compare. 

 

I have never used the RX Gain setting you mentioned.  Experimenting with it, looking at the spectrum display I see it adjusts the noise floor up and down to maybe calibrate it to the actual RX received strength dBm level if you know it so the scale is correct.  Don’t see any impact in actual signal strength and likely unrelated to your low RX level.  I would take a good look at your interconnection cable.

 

From: Charlie Rubenstein <charl...@gmail.com>
Sent: Monday, May 13, 2024 11:42 AM
To: Mike Lewis <k7...@hotmail.com>
Cc: Hermes-Lite <herme...@googlegroups.com>
Subject: Re: External transverter with HL2

 

Hi Mike:

 

I am not using the Optional IO board.  Yes, I have a split IF on the transverter. I have RF3 dedicated RX port connected to the header jumper, but have also tried using the antenna port. I do have the PA disabled. 

 

When I referred to the RX gain setting, I was speaking of the setting in the Xvrtr setup form:

 

On TX, perhaps these settings are why I'm not getting full output. I have VHF0 set to 38.8 instead of 100 like your example.

[Mike Lewis]

Did you adjust your Xvtr TX drive pot?   Did RF1 Tx output level increase?

 

From: Charlie Rubenstein <charl...@gmail.com>
Sent: Monday, May 13, 2024 12:09 PM
To: Mike Lewis <k7...@hotmail.com>
Cc: Hermes-Lite <herme...@googlegroups.com>
Subject: Re: External transverter with HL2

 

P.S.:  I changed the PA Gain to 100.0 for VHF0, and I still get only 15W out of the transverter.

 

Charlie KB8CR

[Charlie Rubenstein]

I still do not receive well on the HL2.  I opened the transverter and the RXGain pot in it is near the top.  On my flex the RX signal is very strong. I'm waiting for another satellite to come over to check again.

The TX gain pot in the transverter is all the way up.

Charlie KB8CR