Hermes transmits but does not receive.

[Alton tschirhart]

After a thunderstorm, I went to use my system and I thought the 80M band was dead.  I saw the normal noise on the spectrum but no QSOs anywhere.  I then went to all the WWV channels and did not see any signals.  I checked the transmitter and everything worked fine.  Something happened to cause no signals but noise to appear during receive.  I wonder is anyone has had the same problem and if it is a repairable solution.  WA5EGG 

[Steve Haynal]

It is likely lightening damaged the ADC. You can start probing the RF IN stages as seen on the schematic when a low level RF signal is applied. It may be that D1 was damaged.

See the schematics here:

www.hermeslite.com

73,

Steve

kf7o

[Kurt V.]

Start from a new database. I suggest to just make a backup of your current one and then start a new one. See if it comes back to life. 

[Jerry Kaidor]

I see that there are protection diodes across the input transformer.  Could they have shorted out?  Steve, what does "DNI" mean on the schematic?

[John Williams]

DNI= do not install 

Sent from my iPhone

On Jul 2, 2025, at 10:56 AM, Jerry Kaidor <jka...@gmail.com> wrote:

I see that there are protection diodes across the input transformer.  Could they have shorted out?  Steve, what does "DNI" mean on the schematic?

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[Marc OLANIE]

Do Not Install;) 

In other words, these components are not soldered 

73' 

f6itu

Envoyé à partir de Outlook pour Android

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From: herme...@googlegroups.com <herme...@googlegroups.com> on behalf of Jerry Kaidor <jka...@gmail.com>
Sent: Wednesday, July 2, 2025 4:56:33 PM
To: Hermes-Lite <herme...@googlegroups.com>
Subject: Re: Hermes transmits but does not receive.

 

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[Alton tschirhart]

It ended up being the T1 primary open.  It could be more but that is a definite issue.   I just happen to see a minute little dot above the ferrite this morning and put on my jewelers head piece and saw the wire attached to it.  I attempted to repair it holding it with hemostats when it flew somewhere in the shack.  I need to know if anyone is or was able to obtain parts from the manufacturer or other sources.  I would like to have a few of these on hand.  It is one component that is not impossible to replace.  Al

[Alton tschirhart]

I can make my own antenna input transformer as long as I could find a source of mini or micro binocular ferrites,.  

[John Williams]

Check the BOM on the HL2 github site. Part numbers in there for all components, I believe. 

Sent from my iPad

On Jul 4, 2025, at 11:08 AM, Alton tschirhart <altsch...@gmail.com> wrote:



To view this discussion visit https://groups.google.com/d/msgid/hermes-lite/63827961-05b0-40d5-90e8-909e5384436cn%40googlegroups.com.

[John Williams]

Kitsandparts.com is a source in the states. You don't indicate where you are located. It is likely a bn-2402 in 43 mix? Bom will have the correct information.

Sent from my iPhone

On Jul 4, 2025, at 11:12 AM, John Williams <jswi...@gmail.com> wrote:

Check the BOM on the HL2 github site. Part numbers in there for all components, I believe. 

[Steve Haynal]

If you are comfortable winding your own, please see the BN43-2402 option on the schematic:

http://hermeslite.com/

The circuit board footprint accommodates this larger T2.

Some people remove T2 and replace with this BN43-2402 as it has better performance on the VLF bands. Search this list for T2:

https://groups.google.com/g/hermes-lite/search?q=T2

73,

Steve

kf7o

[Clifford Heath]

I can make my own antenna input transformer as long as I could find a source of mini or micro binocular ferrites,.  

If you are comfortable scavenging, every gigabit Ethernet magjack has either 8 or more usually 12 small ferrite toroids inside. A discarded Cisco 24 port router therefore has 288 toroids. There will be enough resin that you’ll break a couple opening them up, but you can’t beat the price. You probably don’t need a binocular ferrite.

They are designed to pass signals at 250Mbps, so are perfectly adequate for HF.

Clifford Heath

[Alton tschirhart]

I ordered 5 ea  T1 antenna transformers for $1 each and shipping $8.  As you HL2  owners know, they are super small.   mou...@hotmail.com  is the email I ordered from.  That is not the total problem, FPGA got blasted also.   I have a source to try and replace that for me.  Thunderstorms come at such a sporadic time,  it is best that I get into the antenna disconnect habit.  Al

[Steve Haynal]

Hi Al,

I don't see how your HL2 can transmit if T1 is damaged as indicated by the subject "Hermes transmits but does not receive." There is also the option to wind your own and use a common BN43-2402 for T1.

73,

Steve

kf7o