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Discussion Starter · #1 ·
Hi all,


Between these two signal grabbing monsters I've logged UHF stations from West Virginia to Missouri,and from Alabama to Iowa.


I've been at this for the last six hours so I feel like a zombie right now.Must've logged close to a 100 stations.


I'll give a full rundown on the new Televes aerial later.
 

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This sounds great.


When you have time could you tell us which model Televes you used (1094 or 1046 I suppose) and how you combined the outputs from the two antennas (or did you simply switch between the two).


Did you use preamps? If so, what model?


I also noticed that the Televes "Nova electronic antenna" has a very good polar plot for what appears to be a relatively short antenna. Did you try this one?


Also, let us know your local topography - trees, mountains, hills etc.



Thanks
 

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Discussion Starter · #3 ·
Hello cymro!


You got me hooked on these foreign *aerials*,especially this Televes brand.The build quality is absolutely superb.Very sturdy and all the pieces fit together perfectly.I like the way they incorperate the balun(75ohm output),right on the antenna.


Too bad it didn't come with any instructions.Easy to figure out, though.


I ran a CM 7775 on the Pro Range 75(1046) and a CM 7777 on the DY28A,set to full range,as it does very well on VHF also.


All amplifier products from the UK use power supplies that are 220V,I think.May be hard to use here.


The terrain here is relatively flat,just lots of tall trees.No multipath problems like you have in CA.


These two antennas work much better for me as I like to Dx UHF.Overall,better than the CM Para-Scope,with less windload.


BTW,my longest hauls the other night:

Analog-KHIN Red Oak,Iowa 533mi.

Digital-KSDK St Louis,Mo 266mi.


Purchased Pro Range from www.cpc.co.uk $84.40 incl. shp and got it in 3 days(UPS-Air).Really nice people over there!

www.televes.com.


All for now,gotta go out of town.
 

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Thanks for the info. on where to buy.


The Televes products have great gain specs., but they don't tell you if the gain is referenced to an isotropic antenna (dbi) or to a dipole (dbd).


A gain of 12.15 dbi is equal to a gain of 10 dbd.


The Blake antennas specify dbd. It will be interesting to see what Televes uses.


I sent an e-mail to Televes on Sat. eve. and got a response from an actual person (not an automatically generated response) by Sun. a.m.!


I have now e-mailed them with my question about the gain spec.


BTW, two of their mast head preamps. specify the lowest noise figures I've ever seen for a commercial product. You can buy a wall wart adapter from Radio Shack which takes in 220VAC and delivers the appropriate DC voltage to the mast head preamp.


One preamp. is #5035 which is band limited to ch 52 to 78 (US), but has a noise figure less than 1.5db. This is 0.5db better than Channel Master preamp. #7775, but of course #5035 is band limited. However, the #7775 has better overload characteristics (about 320 millivolts) compared with about 120 millivolts for the #5035.


Another preamp for UHF, #5709, presumably for the complete UHF band, is also less than 1.5db noise figure, but has an IEC connector instead of an F connector.


The 0.5db noise figure improvement over Channel Master preamps. is like having an antenna with 0.5db more gain. Antenna designers kill for gain improvements of 0.5db
 

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I've bought British antennas before at my work. We found out the hard way they use dBd; referenced to a 1/4 wave dipole instead of dBi for an isotropic radiator.


So, yeah you lose 2.1 dB. This makes their gain specs more inline with American offerings of similar design.
 

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I heard back from Televes and their gain figures are all dbi (db ref isotropic antenna).


Their highest gain antenna is the Pro 1046 with a gain of 19dbi at the higher channels. This corresponds to a gain of 19-2.15 = 16.85 dbd (gain referenced to a half wave dipole).


For comparison, the Blake JBX21WB has a peak gain, also at the higher channels, of about 14.5 dbd.


So, on an "apples to apples" basis, the Televes has a usefully higher gain, by a very significant 2.35 db, than the JBX21WB. The boom length of the Televes 1046 is shorter (72 inches ) than the JBX21WB (103 inches).


Compared with the JBX21CD, which has a high channel gain of about 16.25db, the Televes has a gain improvement of 0.6 db. However, the JBX21CD gain drops off rapidly below about channel 50, whereas the Televes 1046 maintains a gain of 14 dbi, or 11.85 dbd down to channel 14.


On paper, the Televes is a better choice than either the JBX21WB or the JBX21CD for complete UHF band coverage.


Of course, only testing will prove this.


I hope to get together with Glenn to arrange for a continuation of his well known Mt. Wilson "bakeoff" tests (which have already covered the Blake JBX21WB and many other antennas) to include the Televes 1046.


Do a search on "Wilson" to find the extensive thread that Glenn initiated.
 

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This a great topic. Please continue to let us know your results.
 

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I need to correct my previous post on 11/11...


Winegard and Channel Master both use dBd. This means they use a 1/4 wave dipole as the gain reference. I had incorrectly stated it was dBi.


Televes uses dBi, as noted by Cmyro. dBi means the gain is referenced to a point source. That means a tiny dot; something small.


What's my point? It means my original point was still correct, but for a reversed reason ;) When you compare American antennas to Televes you must subtract 2.1 dB from Televes to use the same scale.


Example:

Winegard PR4400 (4 bay bow tie), Gain at Ch69 = 11.6 dB.

Televes 1083 (4 bay cats whisker), Gain at Ch69 = 14 dB.


Not exactly a 2.1 dB difference, but nobody said they were identical either :)
 

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cymro,


Where did you get the Televes antenna?

Art
 

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Art


I don't have a Televes antenna yet.


MAXHD ordered it from a company in the U.K. for about $85.00 incl air freight. See post above. I just sent off an e-mail to get a quote.


If you're interested in low channel #'s, the Blake DY28A has the best gain by far: about 18.3dbi from US channel 14 to 35. This beats all others I have looked at by a fair margin. It ought to be pretty directional, but no data is available.



Jeff:


Thanks for your post about the dbd ratings of the US antennas. You are correct: subtract 2.15db from Televes gain specs. to compare with Blake and US makers specs.




BTW; Televes is a Spanish company; Blake is a British company so, as usual, the UK and the continent don't agree (this time on dbd vs. dbi). I'm reminded of the headline supposedly in a British newspaper:


"Fog in Channel: Europe isolated"


Just the attitude for an island race of people!
 

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Hey guys! I'm also interested in the Televes 1046 particularly due to its shorter boom which would enable me to place it in a section of the attic that my CM4251 & APS U-92 will not go. I checked on the website and Echostar is Televes US distributor- Did anyone get a quote from them?
 

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I checked with Echostar, but they don't distribute the Televes antennas; they only distribute some of the other Televes products.


I checked about dealing directly with Televes and they said they were not set up to deal with oneseys or twoseys orders.


Them MAXHD kindly gave us the reference in the UK.
 

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Quote:
Originally posted by cymro


If you're interested in low channel #'s, the Blake DY28A has the best gain by far: about 18.3dbi from US channel 14 to 35. This beats all others I have looked at by a fair margin. It ought to be pretty directional, but no data is available.
Cymro, Missed the link MAXHD posted earlier. The channels I'm interested in are 38,39,41 & 49. I've got the Blake JBX21WB and think the CM4248 may be a tad better. My problem being multipath. Art
 

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Discussion Starter · #15 ·
cymro,


The confusion concerning gain specs/reference is why I didn't post gain spec differences between the Televes and the Blake,and the Blake vs. the CM4251 dish in my previous thread.


The singlemost reason for me to try these antennas was to duplicate,or improve reception compared to the 4251 for Dxing UHF and reducing the windload,especially with Winter just around the corner.Those dishes can ice up,pack with snow,and create 600-800lbs.of sideload forces in 60mph winds.My tower install is not capable of withstanding this worst-case scenario.


In my own non-expert,unqualified observations,the above goal was met,or exceeded.I won't know for sure until I put the Dish back on the tower(where the DY28A is now)and compare it to the PRO 75 for overall performance on the entire UHF band.


I'm curious about the design of the PRO 75,but couldn't find much info on it.Webtv won't download pdf files to get mfg.specs.either.It was mentioned on a UK newsgroup that the three director booms were additive in nature(15ft.total length),and that's how the gain is elevated to a high degree.Way above my head here.


Now that you brought the subject of pre-amps up,maybe that will be a future upgrade.That .5 noise floor spec certainly has my attention!


Check this out.They use these,along with high gain aerials,for weak signal areas combined with hilly terrain.Does this sound *locally familiar*?


Got this http://users.quista.net/researchcomms/p2.htm


from here, http: www.wolfbane.com/articles/supplier.htm



Art,


One of these amps,combined with a Group B aerial,JBX21B or a Unix100(Triax)should work well for you especially if you have a Samsung STB(no analogs to overload it?)


Could this be the ultimate setup for DTV?
 

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MAXHD:


I wrote (e-mail & regular mail) to Research Communications about a year ago regarding these enticing LNA's, but they never replied.


These amps use Gallium Arsenide integrated circuits for the front end.


I'll try writing again.



Look fwd. to your test results.
 

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I received a prompt reply from Research Communications regarding their 98030 preamp.


The noise figure is 0.5db; the overload point is about 45 mVolts, but they don't specify whether this is at the input or at the output. If it's at the input, then the overload spec. is the best I've seen. If it's at the output then the spec. is the worst I've ever seen. I'll ask them to clarify. (I suspect it's refered to the input because GaAs FET preamps usually have the best overload characteristics).


Unfortunately, the price is in nosebleed territory:


195UKP = about $285.00 plus shipping.


Available in 2 to 3 days.


Using this preamp (at 0.5db noise figure) instead of the Ch Mstr (at 2db noise figure) is roughly equivalent to getting another 1.5db of antenna gain. All things being equal, a 1.5db antenna gain increase is achieved by increasing the boom length by about 50%. For DXers this is a serious improvement.
 

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That amp along with the 1046 could give you about a 3.5db gain. That should make a noticable improvement.:) That is, IF the specs are correct.
 

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MAXHD


I sent an e-mail to cpc.co.uk requesting a quote on the Televes 1046. It's been a few days now without response.


I couldn't find any Televes info. on their web site, so I'm wondering if this is the right company.


I'd appreciate any help you can give to get hold of the right people for the Televes antenna.


Thanks
 

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Discussion Starter · #20 ·
cymro,


Be more than happy to return a favor.I jumped through several hoops myself before I found a place to buy the Televes.After sending three emails to different companies that sell them,with no response,I decided to post on news group uk.tech.digital-tv.A nice fellow named Andy Sinclair said CPC was the best place to buy one and give me the link.


I decided to call instead of using email.Got right through.


Sales line-01772 654455

Fax line- 01772 654466


Had to drop the 0 to dial direct(using AT&T).


Sales Rep's name was Dan Gibbs.

CPC part number is AP00759.


Got the 4251 up this morning,comparing it to the Pro Range right now.Will post later this evening on final results,channel-by-channel.
 
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