Transverter Gain

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  • Question
  • Updated 5 months ago
I have purchased one of those 144 Mhz transverters from the Ukraine.  

I've been having some difficulty getting it to work properly.  Basically My received audio is extremely low.  I can hear things from my HT if I turn the RF Gain all the way up but even then the received audio is really faint. (Just barely over the noise floor)  I reached out to the maker and the only response I got was that it was tested prior to shipping and to reach out to the community for assistance.

I'm certainly not blaming the transverter and it has to be something that I'm doing incorrectly, or a setting that I missed somewhere.

The transmitted audio from the Flex through the transverter sounds great.  Loud and clear into my HT.

Any ideas?

Thanks
Chris
NZ6T
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Chris

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Posted 5 months ago

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Danny K5CG

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From Ukraine. Saying "the Ukraine" is like saying you're going to use this transverter in "the America". Very commonly said, but incorrect.
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Pat N6PAT

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My neighbors are from Ukraine and I often catch myself saying The Ukraine. It's a difficult habit to break because I was taught that in school
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Chris

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Huh, never thought about that.  I'm fairly new here and don't see an option to edit my post.
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Danny K5CG

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It's not a big deal Chris. Looking ahead...
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Winston VK7WH

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On the other hand, you would say you were going to user in “the United Kingdom”.

I’m also just being picky.
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Cal Spreitzer

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Hi Chris,  

1.  What Flex Radio are you using with the XVTR? 
2.  What values do you have entered in your Radio Setup (XVTR TAB)?   I'm curious what you have entered for RX Gain (db)?    
3.  Did your XVTR come with the attenuator board?   If it did,  did you bypass it for use with the Flex radio? 
 

Cal/N3CAL

(Edited)
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Chris

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I'm using the Flex 6600

Values on the XVTR Tab:
Name: 2M
RF Freq: 144.000
IF Freq: 28.000
LO Freq: 116.000
LO Error: -330
RX Only: Disabled
Max Power: 3.0 
RX Gain: 20

I used these values (Except for the error) based on the documentation that came with the Transverter.  The Error I figured out by keying up my HT and seeing the signal on the panadapter.  That helped me figure out how much I needed to adjust.

I ordered the XVTR without the Attenuator board.  I guess it's always a possibility that he sent me one with, but I don't think it's too likely since he also sent the documentation for the xverter without the attenuator.
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Cal Spreitzer

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All your settings look good.   On the 6600 under Ant (left side of SSDR) what if any RF gain/pre-selector do you have selected?  Does cycling through the pre-selectors change you HT signal strength at all? 

I used an Elecraft XG3 handheld RF signal source to inject a 2m signal into my transverter.  If you look at the schematic you can see there are a few inductors in the circuit.  You could try and adjust them carefully to see if the signal comes up.  Just remember where they are set initially. 

Cal/N3CAL
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Mack McCormick, Elmer

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Chris,

Do you or a friend have test equipment? If so it would be easy to inject a signal into the transverter, of known values, and look at it in SmartSDR which is very accurate for amplitude and frequency. Please send a description on how you have the transverter wired. Please also send a screenshot of your transverter settings in SmartSDR. 

By the way you can use an antenna analyzer (that works at the appropriate frequency) to inject a signal into the transverter for testing. DO NOT transmit with your antenna analyzer connected to the transverter or one of the ANT 1 or ANT 2 ports with the analyzer connected or you will smoke the analyzer.

73,

Mack
W4AX
Alpha Team
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Chris

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I don't have access to test equipment. What I have been doing to determine the frequency/error is keying up on my Baofeng then switched up to my Kenwood TH-D74a.  I can key up on it and see the carrier on the waterfall.  Just unable to hear anything.  



2M/440 J-Pole -> VHF ANT port on Transverter
RX/TX port on Transverter -> XVTR A.  
PTT -> PTT
(Edited)
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Chris

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Thanks!  As soon as I get off work I'll get that info for you.

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Ed Johnson

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He is talking about Audio gain on receive I believe.  The transverter does nothing with receive audio as it simply moves the 2 meter signal down to 10 meters.  Check the volume setting in two places in ssdr.  Look also at the AGC setting.  It needs to be around 40-50.  What is the level in DBM of the spectrum scope with no signals (in dbm)?  I have the same transverter and all works fine.  
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Chris

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That is correct.  When I transmit everything appears to be working properly...  When I'm receiving either the volume is extremely faint or I'm not receiving any signals at all.  

For example:  

I have the local repeater up right now on both the Flex and an old cheap Baofeng UV-5R.  I'm hearing the repeater on the Baofeng.   I am not able to see/hear anything on the Flex.

When I'm in FM mode on 2m I don't have any AGC settings.  

With the RF Gain set to +16dB my level is currently -160
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Ed Johnson

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Sorry, was thinking 2m ssb lol. Go to "ANT" on the left of your spectrum graph and open it. Set RF gain to 16  and RXAnt to XVTA.  The baseline level should be about -112dbm with those settings. -160 suggests no Rx antenna (assuming the transverter is ok.  Since you appear to be transmitting ok its not likely the vhf antenna, but if you have no way to verify that the 3 watts is actually arriving at the antenna, it might be a good idea to verify rf cabling if you have not already done that.  My guess is the Ant might not be set to "XVTA".
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Chris

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I'm extremely new to Flex... only had it about a month and still figuring out all the features luckily this community, unlike other web forums, is extremely friendly and everyone seems willing to help.

I was referencing the bar on the right where it says -160.  The noise level I believe is showing -129...