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Angelia F3 PTC ("fuse") replacement/upgrade for Protocol 2

Posted: Tue Mar 27, 2018 5:15 pm
by w-u-2-o
It would appear that Angelia FPGA current requirements when running Protocol 2 firmware are in excess of that reliably delivered through the 3.3V PTC ("fuse"), F3.

According to the Angelia bill-of-materials (BOM) published on the Apache web site, F3 is a Bel Fuse O0ZCC0300FF2B, Digi-Key part no. 507-1513-1. It would appear that "O0ZC" is a typo, as searching the Digi-Key site come up with 0ZCC0300FF2B, which looks correct but is obsolete. Digi-Key offers a number of substitutes for that part number.

F3 is an 1812 SMT package. Unfortunately, I could not find a higher rated PTC in an 1812 package. Nor could I find a 0 Ohm resistor or a legit SMT jumper in an 1812 package.

I'm going to modify the Angelia in my 100D, but unless someone can suggest a part that fits, or can be made to fit (perhaps something in a 2010 package, not that I've found anything), it looks like I'll be using a small piece of wire and risking the lack of circuit protection. :(

73,

Scott

Re: Angelia F3 PTC ("fuse") replacement/upgrade for Protocol 2

Posted: Tue Mar 27, 2018 7:46 pm
by W1AEX
That's unfortunate Scott, but you would certainly not be the only one who did that. When I was researching this potential problem with my Hermes - ANAN-100 several users of the ANAN and the original TAPR versions of Hermes said that they went with the wire jumper and never gave it another thought. I haven't found any mention of catastrophic failures to date.

When going down that kind of path my usual fallback response is "What could possibly go wrong???" :?

73,

Rob W1AEX

Re: Angelia F3 PTC ("fuse") replacement/upgrade for Protocol 2

Posted: Tue Mar 27, 2018 8:19 pm
by w-u-2-o
I got a suggestion from the old Yahoo group to go one size smaller, to a 1210 size part. Littlefuse makes a 4.5A PTC, part no. 1210L450SL. If I can get someone to give me a good current measurement I may go with that. It's less than 1mm shy of the pad on each side, easily bridgeable with solder.

Re: Angelia F3 PTC ("fuse") replacement/upgrade for Protocol 2

Posted: Wed Mar 28, 2018 12:55 am
by Joe-W4WT
This should work...

Mouser # 530-0ZCG0300FF2B
Mfr. # 0ZCG0300FF2B

Currently showing 6000+ can ship immediately.

Same part number as original except the 4th letter being a G rather than a C. Unless I've missed something, I see very little difference in the two items.

73,

Joe W4WT

Re: Angelia F3 PTC ("fuse") replacement/upgrade for Protocol 2

Posted: Wed Mar 28, 2018 1:08 am
by w-u-2-o
Hi Joe,

That's the same part I identified up above, and since it's a direct replacement it's unfortunately not applicable to the problem, which is calling for a part with a much higher trip current.

Thanks & 73,

Scott

Re: Angelia F3 PTC ("fuse") replacement/upgrade for Protocol 2

Posted: Wed Mar 28, 2018 1:45 am
by Joe-W4WT
You know, sometimes I wonder if getting older is better than the alternative... sorry for that. I was focusing on the "non-availability" of the current part rather than the obvious problem that you needed more hold current. I'll keep looking around.

Does this affect the Orion MKII boards also?

Joe W4WT

Re: Angelia F3 PTC ("fuse") replacement/upgrade for Protocol 2

Posted: Wed Mar 28, 2018 2:06 am
by w-u-2-o
Nope, the Orion and the Orion MkII are supposedly good to go. I hope! ;)

73!

Scott

Re: Angelia F3 PTC ("fuse") replacement/upgrade for Protocol 2

Posted: Sun Jul 15, 2018 8:28 am
by F1HDI
Hi,
On two anan100D (angelia) running protocol V2 and thus Thetis, I am seeing the following issue and wonder if this could be related to the 'fuse' issue described here :

- tests conditions are two anan100D, one from the early batches (rev16, low perf 10MHz tcxo) and an upgraded one (rev24, CWT817 tcxo)
- tuned on 10,1387 USB
- VAC 4.14
- Thetis
- a leobodnar GPSDO trimmed on 10.1397 (visible at 1000Hz offset in th wsjt waterfall)
- wsjt-x 1.9.1 wspr mode
- let & go
- spectrumlab in // on the same audio stream with very high resolution (I can see better than 0,1Hz)

I see frequent 'clock restart' like the one I have when powering on the radio.

What do you think , should I move to a bigger fuse, which one ?.

73 Jean-Marc

Re: Angelia F3 PTC ("fuse") replacement/upgrade for Protocol 2

Posted: Sun Jul 15, 2018 1:18 pm
by w-u-2-o
Couldn't say for sure, Jean-Marc. I don't know what a "clock restart" is.

The only PTC that's been identified that might work is the 1210L450SLWR identified above. As far as I know, nobody has tried it yet. However, thanks for reminding me, I'm going to order a couple of them from Mouser right now!

73,

Scott

Re: Angelia F3 PTC ("fuse") replacement/upgrade for Protocol 2

Posted: Mon Jul 16, 2018 7:03 am
by F1HDI
Hi Scott,
A quick 'back' on my anan100D#1 from V2 to V1 this morning show No sign of osc instability either on warm-up nor (after 1 hour) on regular basis. I am not very familiar with the features of this forum but can send measurement pictures to you.

I'll do the same measurement on my 100D#2 later on but strongly suspect that the inrush current requested by V2 partially 'blow' the (rearmable) fuse on the board, making the voltage dropping too much and thus creating some kind of instability.

Do you know of some angelia users using V2 ? which mods did they apply (strap of the fuse ?, fuse replacement ?)

73 Jean-marc

Re: Angelia F3 PTC ("fuse") replacement/upgrade for Protocol 2

Posted: Mon Jul 16, 2018 10:44 am
by w-u-2-o
As far as I know, only one person has modified their Angelia and they used a small bit of wire. When I get the part I just ordered (see above) I am going to try that.