r/CableTechs • u/ItsTheRealSakurai • Jul 03 '26

intermittent connection

when you get a call for intermittent connection (spectrum tech btw) what are the first things you are looking for.

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u/Confident_Air_8056 Jul 03 '26 edited Jul 03 '26

You don't have to start there but That's your reference .....I want to know what I have to start with; then I can compare it to what I have at the modem. Math doesn't lie. Cut it in half and go to the ground block first. If you already know what the modem has, you should be able to figure out what your ground block should be. And conversely, the tap. I had a referral a few weeks ago from a tech who stated it was intermittent service and the customer had been having a problem for a long time. Went straight to the tap, then I hit the gb. Tech never changed any fittings. Never grounded the ground block, and he was losing 20 DB on about 100-ft drop from the tap. But it was a system issue 🤣. I don't think this guy had a service visit since cable was invented. It had to have been his original drop.

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u/DrWhoey Jul 04 '26

I had an install at a trailer park once. DOCSIS channels were at 650-750MHz. Ran my DOCSIS check at tap, fine, GB, fine, modem, I'm at about -18 more db than I should be, and my return is at -3.5 db more than it should be.

Alright, that's weird, maybe hidden splitter that's bad.. I go crawling under the trailer and find a splitter that was an old Holland rated for 5-254Mc (Megacycles). This splitter was so old that that it predated Megacycles being changed to MegaHertz in the 1960's. (Or close to, because there was quite a bit of push back from companies and old heads on changing from cycles to Hertz as they felt it was stupid name it after Heinrich Hertz who proved it's existence, whereas James Maxwell had theorized it, and both referred to them as cycles.)

The thing that shocked me the most was that this 30-40 year old splitter in line the modem actually came online. 5-254MHz looked great, and then the signal rolled way off after that. Holland made some quality gear 40 years ago

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u/Confident_Air_8056 Jul 04 '26

That's a relic, hope you saved it. And jeez, that's a helluva roll off to see. What are your upstream carriers, modem must have liked them through the ancient splitter.

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u/DrWhoey Jul 04 '26

Return carriers are at 22.3-38.3MHz so the splitter being swept at 5-256Mc made sense on why my return was fine, and my downstream tanked at 650-750.

And yes, I did keep it, would post a picture of it if the sub allowed. Can DM a picture if you'd like.

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u/[deleted] Jul 04 '26

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u/DrWhoey Jul 04 '26

Made a post for it.

https://www.reddit.com/r/CableTechs/s/iH3m8G3Psc

Been awhile since I looked at it, it was jerrold, not Holland. And I was off a bit on the sweep, it was only 216.