Products > Test Equipment
Siglent SPD3303X-E Binding Post Issues - Solved
Gandalf_Sr:
My SPD3303X-E had the binding post issue - the banana plugs would not grip firmly in the binding posts and, despite Siglent sending me new binding posts, the problem persisted - regular banana plugs would fall out of the binding posts at the slightest touch. Today I did some research and figured out what was wrong. In the diagram below, you're looking at a cutaway of the end of the binding posts; the banana plug needs to go 6.64 mm into the post before it even gets to the actual 4mm ID connection (this is a much greater distance than most binding posts) and the internal diameter of the hole (where the colored inserts are = shaded area)) is only 4.5 mm which means that many banana plugs won't fully insert because they have flared flanges that take the actual plug into the insulated support. The solution was simple, just drill out the end of the colored insert so that it's at least 5.5 mm ID, I found a stepped drill bit that was perfect to achieve this with minimal fuss.
I'll follow up with pictures of the whole process
Gandalf_Sr:
Here we go withe the pictures. In the first set, the top (black) post has been modified but the bottom (green) one hasn't, note that the plug doesn't go all the way into the bottom one.
Then we see the step drill - I got this from harbour freight and tool and the step marked with a dot is 7/32 5.56 mm) and the smaller steps work as a guide - you carefully drill into the end but don't push too far.
The final set show the actual PSU modified, in the before picture you can again see that the plug doesn't go all the way in, after the mod is does - it's only a difference of about 1 mm but it makes the plugs stay in well.
tautech:
Thanks, very interesting !
When I look at the banana plugs you've been having problems with it seems from the center of the 'lantern' spring to the shoulder of the plug the distance looks quite short, in that the lantern in not engaged past it's midway point.
Then of course they'd just fall out !
I've looked at this issue for members here and myself when I bought the first of these models in when reportably the binding post issue had been fixed.
With any of the banana leads I have I found no issues with loose plugs and have posted several times to that effect.
So I've just measured some stackable leads that have retractable shrouds and the total pin length was 16.25mm and the 'lantern' spring center measures 10mm from the pin shoulder/base.
That would place the center of the 'lantern' ~3.5mm past the step without modification of the binding post.
This style works perfectly with these Siglent PSU's.
Yours don't look that long, can you measure them please ?
And for Siglents benefit (emailed) please list their manufacturer and Pt # ?
Gandalf_Sr:
Tautech, I have about 6 different styles of banana plugs, only 1 type works with no issues in the SPD3303X-E binding posts. All the other equipment that I have with binding posts, including cheap Chinese bench PSUs do not have this issue with any of my banana plugs.
The point of my post was not to get into a long list of which plugs work with the SPD3303X-E and which don't, it was to point out that there is a problem with the particular binding posts Siglent chose to fit on the SPD3303X-E - I identified why they were problematic and I described a simple way to fix it.
If Siglent want to change the design then good for them. If users want to buy multiple plugs until they find ones that work, they can do that; or they can try my simple modification.
tautech:
--- Quote from: Gandalf_Sr on March 05, 2018, 12:12:12 am ---Tautech, I have about 6 different styles of banana plugs, only 1 type works with no issues in the SPD3303X-E binding posts. All the other equipment that I have with binding posts, including cheap Chinese bench PSUs do not have this issue with any of my banana plugs.
The point of my post was not to get into a long list of which plugs work with the SPD3303X-E and which don't, it was to point out that there is a problem with the particular binding posts Siglent chose to fit on the SPD3303X-E - I identified why they were problematic and I described a simple way to fix it.
If Siglent want to change the design then good for them. If users want to buy multiple plugs until they find ones that work, they can do that; or they can try my simple modification.
--- End quote ---
Sure.
A measurement to the center of the lantern of the 5 types you have and have trouble with will help others select what WILL work and give Siglent some info of different shoulder to lantern lengths that they maybe don't encounter in their part of the globe.
I know 10mm to shoulder works, what length are the problem ones you have ?
If we know that, then we can select banana plugs by measurement and not have to buy a selection rather than as you put it: 'buy multiple plugs until they find ones that work.'
Navigation
[0] Message Index
[#] Next page
Go to full version