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andrewlace

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About andrewlace

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  1. This is a really good thread. Sorry I got in so late. Generally for digital modulators they run 80+ dB signal levels. I would advise not have a splitter going into two amps. A dw42 works fine but as a rule there are better launch amps out there but at three times the price (you're paying for the extra headroom and channel load). Dw42 offers the best bang for buck. With that channel load don't expect any higher output than 108dB on the highest channel before overdriving the amplifier. A band pass filter on the antenna side will help improve mer and reduce noise. A splitter is an awful way to mix signals. At least they have increased the isolation by using an amplifier on the antenna, but at the same time increasing distortion on the Fta channels. I would be cascading some drop taps (directional couplers) reversed to mix the antenna and balance signal levels. Assuming the antenna feed is 60+ dB you shouldn't need a masthead amplifier. If you do need a masthead amplifier put a band pass filter on the input stage (after an amplifier may work with the launch amplifier but is not ideal). You could also use a diplexer, however you'll likely find that the channel levels from the modulators are too high and need to be brought down. Three basic amplifiers for this system and no filtering is not ideal. A reversed tap means the input becomes the output and vice versa. They also have a better impedence match and heaps better port to Port isolation. For four digital modulators I'd be using a four way tap into the tap sides for the modulator and assuming the levels are high enough 62+dB into band pass filter (if not put the band pass filter on the masthead amplifier input feed) then feed the aerial into the labelled output on the tap. The labelled input (becomes your output) on the tap then feeds into the distribution amplifier. Choose a suitable tap value based on the difference between the antenna input levels and modulator input levels. Sorry I didn't catch this sooner I hope this helps in the future. What brand of modulator are they? What are your levels? Let me know if this helps. I've found on a lot of systems a mda20 is better than a dw42. It has less noise and more headroom, but no gain adjustment but a lot less gain. Kingray makes both products and if you don't need the extra gain the mda20 is an outstanding product and incredible value for money. Most good antenna wholesalers should be able to supply you.
  2. The fracarro phased array is a good suggestion. James has suggested the mda20u I can verify that their range on amplifiers works where nothing else has. It may be worth seeing if anyone on the forum covers your area. I use a unaohm ap01 as a meter and the number of times I've done a job where 3 other guys couldn't get results and didn't know what a spectrum analyzer is our how to use one is bewildering. A good meter and technician is obviously crucial. I recommend in weak signal areas to only add filtering as absolutely necessary. The narrow band Yagi's that fracarro make do amazing things. Some of the new wisis have a LTE filter inbuilt which brings
  3. Six years later and filtering still does not reduce the errors. It reduces noise which may or may not be the issue. There are narrow band aerials which have higher gain and good band selectiveness, narrower beamwidth etc, and there are products like the mda which now have additional filtering built in. I've used heaps of kingray mda20l and the low noise design, high headroom and little or no filtering has meant I've used it for amplifying c band satellite at a stretch and FM in weak signal areas with little harmonics. The audiophile customer was blown away and I was very happy too. Band pass filters are now cheap and very effective you can choose which channel block you need. Lacey's TV have these.
  4. Forgot to mention the yagi brought the my Dandenong up 6dB and the lte down about 20dB
  5. Forgot to mention the yagi brought the weakest mount Dandenong signals up 6dB and the lte down about 20 dB
  6. At the lte issue ran across another one today. 43dB channel 7 and 10 digital Melbourne, Cheap low gain combination 3 4 antenna with low gain. Chucked a yagi and took a cheap distribution amp out. Lte was at 70 dB no amp no worries ? dang shame I followed my GPS getting there though. Lol.
  7. Good points MLXXX, a few people stopped getting excited about this forum due to the stupidity of others. Forum moderators are responsible for this mainly, I've also seen much advice and no field experience coming from said person. I don't like being told "remember" hey I do this job everyday. I have some great friends who are former broadcast engineers. I like to study different products to come up with viable solutions to simple issues. But I know I can be arrogant hence my comment about my experience the ones on here that seem to know the most only use it when necessary and with discernment, rather than pretending to be an authority.
  8. Yeah I'm on the peninsula replaced a 5 year old one a week ago. There are heaps of them here. Every time someone says it goes nuts at any time, amp is an am126 on the mornington peninsula they were a best seller. I want my installations to be working when I can't.
  9. Yeah I'm on the peninsula replaced a 5 year old one a week ago. There are heaps of them here. Every time someone says it goes nuts at any time, amp is an am126 on the mornington peninsula they were a best seller. I want my installations to be working when I can't.
  10. Hi this is a duplicate post. Recommend not using that amp. According to the box it has 100dB gainhttp://www.bunnings.com.au/antsig-8-way-indoor-vhf-uhf-distribution-amplifier_p4360394 ROFL this product is another example of why there is always going to be a market for quality antenna technicians 10dB x 8 is approximately 26dB gain. If the amplifier's not a low noise solution and has a split or mixed input. Kingray and fracarro both make excellent amplifier solutions, aerial industries also have lte filtered amplifiers.
  11. Can definitely be done but will require either a dedicated commercial solution for iptv or raspberry pi and xbmc type solution. I'd be worried about sufficient bandwidth. If you can run optic fibre data and tv should be a doodle fibre is a lot cheaper than what it was and much faster than wifi even using a dedicated apn and won't need a bunch of raspberry pi units abs external tuners configured to stream to other raspberry pi units. Coax degrades much faster than fibre. You can run data and tv and numerous satellite services down the one fibre. You can even get the ends preterminated. I'd hate tti set it all up and find I don't have the bandwidth to do several HD channels.
  12. According to the box it has 100dB gain http://www.bunnings.com.au/antsig-8-way-indoor-vhf-uhf-distribution-amplifier_p4360394 ROFL this product is another example of why there is always going to be a market for quality antenna technicians 10dB x 8 is approximately 22dB gain, high noise 12dB insertion loss. As your amplifiers from bunnings if your aerial is from there I'd suggest going passive (no amp). Try a Fracarro terza6hd from Laceys.tv Brisbane. Say G'day to Ash, he's a top bloke and knows his stuff. The antsig products are definitely not in the same class. If you can run a system with a good aerial and no amp your laughing. They have a range of quality splitters. I love bunnings for their range of hardware, but they are not an industry specialist. Ash will likely know the good local technicians as he is a smart guy. I do install work in Melbourne.
  13. Hi beeblebrox, yeah I like the cast casing on the old mda20. I've seen a few pcb only Kingray's fail due to corrosion. It's an expensive case to manufacture though. I know almost every amplifier has the same issues unless you go nuts with silicone lol. Which alcad are you using?
  14. Oh dear I went out there over 18 months ago so it wasn't lte that was the issue. I was there for about 15 minutes and never charged for my time. Grant is in an area known by locals for for being difficult. A lot of the homes are built on the side of a hill. LTE is an issue, not the issue. Kingray do not filter out cb bands on all their amplifiers. I know this as a lot of pubs use their amps to run s band analogue. You should run a noise gen and spectrum analyser to test a product before declaring then effective as filters. I have said it before narrow band yagis are a great cost effective way of filtering lte, cb radio and most interference. A wideband uhf yagi or log periodic is not advisable. Most filtered lte amps are greatly inferior to many dedicated lte filters on the market. That said agreed it is not wise to rehash don't use a log periodic, use a lte filter, trust me on the sunscreen speech. Kingray make some excellent amplifiers but filtering out anything out of the tv band magically and with low noise, even their budget products, that they don't do so well. As previously discussed the mda20 is vastly superior but with little or no filtering. Melbourne doesn't use block e so a narrow band yagi can smash most lte issues. We need to remind ourselves that a lot of issues are resolved with the correct antenna and no amplifier. A cheap amplifier and antenna is an expensive solution to a simple problem. Most interference issues can be resolved by removing amplifiers and installation of a suitable quality antenna. As I saw earlier with a chap trying to get Melbourne cbd transmitter off a terrible combination antenna polarized horizontally (cbd needs 40-44 vertical from memory). It would be cheaper and simpler to put a narrow band yagi on designed for block e 10/4046r does an awesome job at this and can be used for either polarity (oddly enough I used to use these for Gippsland back in the day). With grants place someone needs to do a full site test. Grant was keen to point out access issues, as with anything if you can't safely get to the masthead amplifier and aerial you don't do the job. That's how you stay in the industry. What was wrong on Grant's job is an issue of conjecture until someone gets access abc fixes it. This may have already happened (could have been an intermittent amplifier) as is often the case. Half the sites on the peninsula with amplifiers use alcad am126, a product which is legendary for going intermittent after a few years. I'm an active forum member and have been for years.
  15. Thanks for posting that beeblebrox. Have you used many of these? I've still got a few mda20 series left. I've never seen an amp in this price range work as well. I'll have to see what to do when I get down on levels. External filters work great too.
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