Nickel-plated contacts

[Dutchy19]

Really? Are you familiar with MIL-PRF-39012 ( Connectors, Coaxial, Radio Frequency, General Specification for (w/Amendment 4) )?
View attachment 472461

No I haven’t, which was kind of my point. The MIL-STD has classifying nomenclature for gold-plated connectors, but that doesn’t mean you’ll see one in the field. Are there references from typical MIL-STD/STANAG docs or procurements that require gold plating?

 

[Dutchy19]

Checked with a few colleagues. Nobody had seen gold contacts in regular use in equipment and cables for the 2-300 MHz spectrum bands, but had seen some cables like that for infrequent connections on vehicular platforms in particular. Mind you this is for equipment mounted in military vehicles that are rated for outdoor exposures. Pretty harsh environments, definitely worse than my basement den.

 

[Sokel]

Are you sure?

'Influence of output relay contacts to power amplifier distortion'

Aug 18, 2025

My goal is to show how output relay contacts may worsen THD of a high power amplifier. The amplifier under test is this one:

https://pmacura.cz/DIY_250W_4ohm_amplifier.html

and the output relay under test is Finder 40.31.9.024.0000 type with AgNi contacts. It has maximum contact current of 20A and is rated at 10A ac current with resistive load. The tested parameter was THD vs. output power at 1kHz into 4ohm and 2.2ohm resistive loads. Measuring bandwidth was 45kHz.

1. Load 4 ohm

Distortion is same up to 20W/4ohm. Then we can see and effect of nonlinear contact...

• pma
• Replies: 0
• Forum: Amplifiers, Phono preamp, and Analog Audio Review

• 

I have two questions (I could search but your experience is better) :

Is this the case with reed realys too? I have had preamps with such realys and if I remember well the contact material is not advertised as nickel and the sealed nature may help too.

Second, what about the self-healing fuses?
If I remember well from diyaudio the situation there is more severe and it only takes a few times as to degrade rapidly.

Khadas TB has one of them but has not tripped yet, at least to my knowledge, it manifests as pops and such when they trip as I read.
DACs in general can be susceptible at such events from the PC side with lower tier hardware.