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Re: Spurious Emissions

 

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I¡¯d like to point out the ARRL review was published in August 2021 before recent unfortunate events and in addition read in it¡¯s entirety the article could hardly be said to be ¡°shredding¡± the radio. ?In the maybe 20 years I¡¯ve read QST I really remember maybe only one review where they ¡°shredded¡± a radio¡­.even radios that truly deserved to be shredded got ok reviews. ?QST reviews are typically way more positive then they have any right to be.?

Suboptimal transmissions from some Chinese made HTs were also pointed out years ago and then when later Chinese made HTs were cleaned up the QST reviews reflected that. ?

I don¡¯t think anyone has pointed out any errors in the technical information presented in the ARRL review of the TX-500, but if you did find an error certainly you could email QST for a correction instead of accusing someone of being ¡°selfish¡±.?

73,
Tom, N2YTF?





Sent by phone, please forgive my brevity and poor typing.

On May 28, 2022, at 5:12 AM, George MM0JNL <george.crawford72@...> wrote:

?This could also be false reviews but haters of Russia trying to deface a wonderful little radio due to the nation of origin. There has clearly been a lot of work and time gone into this radio and public release was delayed until FCC AND CE approval was gained.

There will always be "experts" trying to shred something they don't like, mainly due to their selfish attitudes. I say take these reviews with a pinch of salt.

Best 73 from a satisfied QRP opp.

Re: Spurious Emissions

 

This could also be false reviews but haters of Russia trying to deface a wonderful little radio due to the nation of origin. There has clearly been a lot of work and time gone into this radio and public release was delayed until FCC AND CE approval was gained.

There will always be "experts" trying to shred something they don't like, mainly due to their selfish attitudes. I say take these reviews with a pinch of salt.

Best 73 from a satisfied QRP opp.
Re: Spurious Emissions

 

A good inexpensive instrument for quickly checking any transmitter for spurious emissions/"spurs" is the TinySA.? It saved me from running a Chinese HT with HUGE spurs, and revealed that another was modestly outside FCC limits.



(May be available slightly cheaper on less-trusted sites!)

73 - KG7ABM
Re: Raspberry Pi

 

Thanks. I am using wsjtx. I seem not to be able to get the audio in and audio out correct.?
Re: Spurious Emissions

 

@KD2VDW,

If you have an ARRL account you can see the full review at this link.?

?

There is some info under "Lab Notes: Lab599 Discovery TX-500" about some low-level signals in CW mode, although at a very low level.??

"On the transmit side, the TX-500?exceeds the FCC¡¯s requirement for?harmonic and spurious suppression, which is 43 dB for HF and 60 dB?above 50 MHz. However, I observed?multiple low-level signals transmitted along with the?intended signal. For example, in CW mode, a spectrum?analyzer typically displays a single carrier, which turns on?and off as CW characters are transmitted. As shown in?Figure D, a spectral sweep ¡À 5 kHz from the carrier, there?are numerous low-level signals also transmitted. These signals are at least 48 dB below the carrier (a fraction?of a milliwatt). The added spurious signals explain the?unusual plot of the CW sidebands in this review, despite?the TX-500¡¯s nice CW waveshaping?(see Figures A and B with Table 1)."??



Allison B, WB1GCM?(August 2021) "Lab Notes: Lab599 Discovery TX-500" QST, Volume 105, Number 8, Page 42

Kind Regards
Tim - KJ4RDF
Re: Raspberry Pi

 

Attached are the settings I use with a DigiRig. I want to say I had the same settings with a generic Audio Adapter as well but i don't recall for sure. I had to go down the list to get it right for both the audio in and out. it also matters what audio is selected in the Pixel OS, screen shots also attached for that.

Lab599 TX-500 DigiRig WSJT-X Audio Input Selection.jpg
Lab599 TX-500 DigiRig WSJT-X Audio Output Selection.jpg
Lab599 TX-500 DigiRig WSJT-X Audio Settings.jpg

Re: Raspberry Pi

 

I'm in the process of putting together a Raspberry Pi 4 to use with my TX-500. You may already know this but the audio jack on the Pi is output only (no mic in). I purchased a cheap USB Audio adapter from Amazon to accommodate this -?
Re: Raspberry Pi

 

Helps to know how you are connecting tx-500 to the raspberry, which software you are using and exactly which part you can't get right
Raspberry Pi

 

Is anyone using a Raspberry pi for FT8? I can¡¯t get the audio right. Any help would be appreciated.?


bob NZ2Z?
Re: Spurious Emissions

 

Of course.
Re: Spurious Emissions

 

It IS important to note if you use an external amplifier. I think that is one of many reasons the DIY599 amplifier has filtering in it.


On Thu, May 26, 2022 at 11:35 AM Pete Millis <pete.millis@...> wrote:
The specs do say spurious emissions >50dB below carrier, and that does appear to be correct. I don't really think there is an issue.

73 de M3KXZ



--
John Byerly
mailto:mtnlion@...
Re: Spurious Emissions

 

The specs do say spurious emissions >50dB below carrier, and that does appear to be correct. I don't really think there is an issue.

73 de M3KXZ
Re: Spurious Emissions

 

Henry, Any way to post the full review?

Thank you
Re: Spurious Emissions

 

Marc,

Try using it at an ARRL Field Day site where there are multiple stations on several bands.? Or, if you have a neighbor ham within a few miles, ask him/her to listen to your transmissions.

I have attached a file from the ARRL Lab In-Depth Review of the TX-500.

73,
Henry - K4TMC


On Thu, May 26, 2022 at 8:50 AM KC9WIB - Marc via <marc.rosen=[email protected]> wrote:
I've used this radio for over a year, I consistently get good reports on audio quality?

I don't know if there is an easy way to see or detect spurious emissions without a spectrum analyzer or monitoring on the receive end - that said I've used it with FT8, FT4, RTTY , CW, and SSB , at times with the PA-500 amp and have NEVER been told "your signal is dirty, overdriven or splattering "

QST in Depth - August 2021 QST - Lab599 Discovery TX-500 Review.pdf
QST in Depth - August 2021 QST - Lab599 Discovery TX-500 Review.pdf

Re: Spurious Emissions

 

I've used this radio for over a year, I consistently get good reports on audio quality?

I don't know if there is an easy way to see or detect spurious emissions without a spectrum analyzer or monitoring on the receive end - that said I've used it with FT8, FT4, RTTY , CW, and SSB , at times with the PA-500 amp and have NEVER been told "your signal is dirty, overdriven or splattering "
Spurious Emissions

 

I have read a bunch of reviews about the radio putting out spurious emissions, Can someone please elaborate on their experiences and the effects?

I have read such great reviews,the ruggedness and size are perfect for me to operate portable.

Thanks
Re: Where may I buy a spare power cable with the 3A fuse?

 

I made my own using 18awg silicone insulated wire which is really flexible. GX12? connectors are readily available on line. Power connectors on line or in RC model shops. I homebrewed my own mini blade fuse holder using 2 spade connectors and adhesive lined heatshrink.?
Quick and easy project.
73 de M3KXZ
Re: Where may I buy a spare power cable with the 3A fuse?

 

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The connectors are generally available on Amazon, as is the wire.? Personally I would have fused both red and black, but that's me.? I put a 2.1mm plug on it so that I can connect a wall wort or use an adapter cable that has? a 2.1mm plug on one end and powerpole connectors on the other end to connect 12v pwr supply or LiFePo4 battery.??

From: [email protected] <[email protected]> on behalf of Winston <win2wang@...>
Sent: Friday, May 20, 2022 1:26 PM
To: [email protected] <[email protected]>
Subject: Re: [Lab599] Where may I buy a spare power cable with the 3A fuse?
?

It took a while to get all of the parts and process worked out to build this power cable. Parts include an in-line fuse holder.
Re: Where may I buy a spare power cable with the 3A fuse?

 

It took a while to get all of the parts and process worked out to build this power cable. Parts include an in-line fuse holder.


0BA2343F-80BB-45A8-B7F8-365B6B693E03.jpeg

Re: HRO acting lame, tx-500 return

 

John,

In fairness, it looks like HRO went out of their way to fix your issues, even replacing the radio! (try that with a new car!)?

In my opinion, Lab599 is "WELL REPRESENTED" by HRO (despite the current Political Climate) and continually strives to support Hams in North America.

Maybe cut them some slack?

73

Terry, ve3ega
1981 - 2000 of 4100