Hermes Lite 2 Amp

[paul chancellor]

Any experience with Xiegu 125 amp and Hermes Lite 2.0 ?

[Reid Campbell]

Hi Paul,

I run the 125B with the HL2 and have been happy with the performance. I done a mod to allow Band Volts to be output instead and Fan PWM (https://github.com/softerhardware/Hermes-Lite2/wiki/Band-Volts), so it tracks band changes.

You only have to run the HL2 in the lowest power setting or it will over drive the amp and I have also added a cooling fan on the side of the 125B. Running FT8 for several hours at about 50-80W will show about 45-50C on the amp temperature display with the fan running.

Cheers

Reid
Gi8TME/Mi0BOT

On 06/04/2021 03:07, paul chancellor wrote:

Any experience with Xiegu 125 amp and Hermes Lite 2.0 ? --
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[Pierre Martel]

HI Reid and Paul.

I was looking at building myself a small HF amp and I fell on this thing while searching for parts on alexpress:

https://www.aliexpress.com/item/4000945095237.html

This look like the same form factor as the XPA 125B.

As I already have a ATU-100 in construction, do you think that this could be a good partner for my Hermes-Lite 2? 

I am a bit weary about something as on the photo of the amp we see a LPF on the side as 3 small pcb's would that be enough to suppress the harmonics of the whole setup?

Let me know your thoughts please

Pierre

VE2PF

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[Reid Campbell]

Hi Pierre,

I see several problems with amp and you should read the thread about "Chinese 100W amplifier problem". Many of these amps have fake transistors, although this looks like it's not a kit so may work out of the box.

The main issue is with the LPF. I never seen a HF LFP with inductors created from spiral tracks on a PCB. I have seen the technique use in VHF/UHF designs, so the inductance created will be quite low. This would mean that the LFP cut off frequency will be high and it might act as a LPF for the highest frequency range of the amp but will pass harmonics for the lower band. This would be a major problem for the 80 and 40 metre bands.

I see no option to exchange or switch in other LPFs, so I can't see it being compliant for harmonic suppression requirements of your licence. I think there are other solutions out there which come from more reputable sources and I'm sure other members of the group could give you more options to go for.

Cheers

Reid
Gi8TME/Mi0BOT  

[runni...@gmail.com]

Hi Paul,

I had an XPA125B driven by the Hermes Lite 2.0 and was running it at about 25 W in FT8 (and others). The PTT circuit was isolated with an opto coupler.

Unfortunately, the PA broke down (didn't power up anymore) after 2 months of fine operation.

Since then, the repair is a nightmare. I sent it back to the seller on Ali Express, who refused to pick it up from customs.

So it came back to my QTH after 3 months. Sent it back via the European distributor to China, and waiting since then .. the story goes on for 9 months now.

Since the XPA125B lacks forced cooling (there is no fan), it can easily overheat ... and break down.

73's Erik

ON4PB

[Sid Boyce]

Hi Paul,
Exactly the same story here.

Mine was to have been delivered to Weilan-aimi in China on 17th.
Augustus 2020, eventually returned from Customs in China about six weeks
ago.

I have requested a refund of my shipping and insurance costs from UK
shippers ParcelForce who are currently considering it.

I contacted a UK company sinotel that sells the XPA125B and was told to
get back back to them when I get it back.
I would have bought from Sinotel if they had showed up as a supplier on
Ebay.
I emailed them a few weeks ago but have not had a reply ... may be
closed due to the coronovirus.

Power OK on to the PCB but amp doesn't power on.
73 ... Sid.

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--
Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot
Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support
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[Brian Holmes]

Hi Erik, but no issue with the PA in the HL2 I take it, just in the external XPA125B Xiegu Amplifier.  

Brian

VE3IK 

Sent from my mobile device. 

+1 (416) 419-3161

On Apr 23, 2021, at 5:53 AM, runni...@gmail.com <runni...@gmail.com> wrote:

XPA125B

[Reid Campbell]

Hi All,

I may be tempting fate but mine's being going OK. I bought of Sinotel
last June. I run it at about 50-80W on FT8 but have a fan which sucks
air from the side of it. The fan has a 40C thermal switch in contact
with the bottom of the case which comes on when the display on the amp
reaches about 50C. The displayed temp then drops down to about 40C. I
sometimes run it like this for a couple of hours on FT8.

I plan to open it up after the year warrantee is up to see it I could do
any mod's. Would like to have a way to remotely start a ATU tune.

I noticed that MFJ had sold there 125B's off cheap. That would worry me.

Cheers

Reid
Gi8TME/Mi0BOT