900 MHz

Discussion in 'Ham Radio Discussions' started by KD7LDH, Jul 18, 2002.

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  1. N7CPC

    N7CPC Ham Member QRZ Page

    Glen, Thanks.

    GOF, I only yawn at "same old ...." topics.

    Again, Glen, good idea on the commeercial radio mods. My first excursions into FM were modified Motorola™ gear.

    To clear up the other point, I took a fifteen year radio siesta until about three years ago. When I reentered Ham radio I became aware of the spectrum and licensing changes at that time. The implied lapse of knolege ended then, not with this post.

    Back to the commercial gear. About twenty years ago I was briefly associated with a cable TV company in the Chicago area. They used nine hundred meg. gear at that time, so there should be lots of aging or scraped gear out there for the purpose. Think I'll start looking. Thanks for the idea.

    73 de Craig...........N7CPC [​IMG]
     
  2. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    By ARS I "assume" that you mean Amateur Radio Service. The only power restriction that I know of on the 33 cm band is within 241 km of the boundries of the White Sands Missile Test Range in New Mexico where a maximum power of 50 watts is allowed. Otherwise, the 1500 watt PEP output rule applies. With gain antennas, this can easily go to 30,000 watts e.r.p. or more.

    As far as Ericsson goes, they still operate around here as Ericsson. However, the name changes, etc., go on and on. Motorola has been in trouble for a number of years. Well into the 1980s, only a Motorola salesman could sell a new Motorola two-way product. Then, with the advent of all sorts of lower priced equipment that an independent dealer could sell (i.e. Uniden, Standard, Regency, etc.), and with many of the Motorola Service Stations starting to sell that equipment, Motorola finally started letting the dealers sell the lower end equipment. Later, they started letting more and more of their lines be sold by the MSS.

    Motorola has always had an attitude. That is, if you want Motorola, you will pay Motorola's price. Well, a lot of people found that they could get equipment that performed as well as, and sometimes better than, Motorola without paying Motorola's price. That was a very rude awakening for them. They have never fully recovered! I know, I owned the Motorola reconditioned equipment center for the south-central US from 1970 until Motorola went out of that end of the business in 1979 (we had 14 states commercial market, anything reconditoned that was exported, and anything that went reconditioned to the US Government - was the height of Viet Nam and the US Government did buy reconditioned two-way equipment).

    Glen, K9STH
     
  3. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    I don't see why there'd be much use for 33cm, 23cm, 13cm or any band above 70cm for FM channelized/repeater work. The 6m, 2m, 135cm and 70cm bands are underutilized and have readily available equipment and better propagation. To use 33cm for FM/repeaters seems senseless.

    However, there is activity on 33cm SSB/CW for sure. In fact, there's quite a lot, if you have the gear and the antenna to really listen there. When I had a large VHF-UHF contest station back in the 1980's in NJ, I ran 250W output on 33cm using an LT33S transverter (SSB Electronic GmbH) and an FT101ZD (good transverter rig), with a homebrew dual 3CX100A5 (2C39) cavity amplifier and made lots and lots of contacts, and worked about 100 grid squares on 33cm. Obviously, there was activity. And there still is. However, without both the equipment and the antennas -- with an emphasis on antennas -- you won't hear anything.

    I used a pair of 45 element loop yagis at the time, made by Down East Microwave, who at that time were in Maine and made some very nice UHF-SHF antennas. Such items are still available.

    It takes some real dedication to explore the UHF-SHF bands. A ground plane on the roof won't cut it.

    Here in CA, the San Bernardino Microwave Society and other UHF enthusiast groups have helped popularize the 33cm, 23cm, 13cm, etc bands, by making gear readily available at the local swap meets and such. But all the gear in the world won't make contacts without serious antennas for those bands.

    Al, W5LUA in Allen, TX (do you know Al, Glen?) has a serious station for those bands, as do dozens -- no, hundreds -- of others. Take a look at VE4MA's station, or W7GJ's, which is featured in the July 2002 QST. Great stuff. But real dedication required. These bands are not for the faint of heart.

    WB2WIK/6
     
  4. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    I know W5LUA (exWB5LUA). Run into him usually on 2 meter SSB. He lives about 12 miles from me. Also know K5GW, who moon bounces like he was working locals.

    Steve is correct about having the antennas. If you only have a roof-top mounted ground plane, especially if it isn't even "cut" for the band, you won't hear much of anything. If the commercial FM gear starts being utilized, then there will be more repeater activity on 33 cm just because of the "nature of the beast".

    Glen, K9STH
     
  5. KD7LDH

    KD7LDH QRZ Member QRZ Page

    For my pager Idea heres how it would work:

    A bunch of computers with Transmitters and internet (and maybe a phone line) are placed tactically around a city. The computers cordinate messages and transmissions to the pagers (through another 900 mhz freq or maybe 1.2 ghz). They receive the messages from everyone on E-Mail and Phone (for numeric paging). They use a the paging POCSAG or Flex protocol or better they use AX.25. The pagers could be old pagers and have a 900 mhz cyrstal installed. How does that sound.
     
  6. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    For LDH: From a technical point of view, this could be done. From a practical point of view, one "heck of a lot" of work to accomplish very little.

    Glen, K9STH
     
  7. N0FPE

    N0FPE Ham Member QRZ Page

    The lack of use on 900mhz or any band for that matter is just as a few folks stated. " I listened and didnt hear anything so I will not use the frequencies"
    6 meters is that way for a lot of folks. They listen one time.
    Here locally a few of us silly hams decided to build a 900mhz repeater. we used 2 Areotron Mega900's for the repeater and found that the EF Johnson 8655 makes a WONDERFUL mobile/base rig for 902 with NO major mods needed. A fellow by the name of Pete Dziomba(N2MCI) sells new CPU's for the 8655's that are direct plugin replacements and allow for simplex/duplex operations on the 902 ham bands using the 8655 with only a simple retune!!!
    Motorola Maxtrac 900's can also be converted but are a bit more involved.

    SO the use it or lose it statement is very true. We built the 900mhz repeater not for the HUGE use it would get but because we could!!! If more folks would worry less abt NO ONE being there and become one of the folks that ARE there the band would be used!!! Why stop at 440mhz??

    And like 220 was a few years ago..Most scanners can not listen there!!!! We can do sneaky ham things up there!!! Ya know like plan raids on competing Field day sites for their BBQ and the like!!!!

    Dan [​IMG] [​IMG]
     
  8. KB1GYQ

    KB1GYQ Ham Member QRZ Page

    </span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (N0FPE @ July 21 2002,08:04)</td></tr><tr><td id="QUOTE">And like 220 was a few years ago..Most scanners can not listen there!!!!  We can do sneaky ham things up there!!! Ya know like plan raids on competing Field day sites for their BBQ and the like!!!![/QUOTE]<span id='postcolor'>
    Now that would add an interesting twist! [​IMG] Foxhunt to the &quot;enemy&quot; camp, and raid their supplies. Perhaps it would foster innovation in anti-RDF equiptment and techniques. [​IMG]
     
  9. K9KJM

    K9KJM Ham Member QRZ Page

    There is all sorts of activity on 900 even out here in the &quot;boondocks&quot; Unfortunatly, it is not amateurs, But commercial devices operating on the so called shared basis. There seems to be more ham activity on 1.2Ghz than 900. The old saying &quot;use it or lose it&quot; I fear is very true. Great post by N0FPE on the Johnson 8655 rigs, How about doing a little article for one of the ham magzines on it! [​IMG]
     
  10. W5ATX

    W5ATX Guest

    Yes, the Maxtrac 900 conversion is a bit technically challenging. But it's doable, no doubt. There's a repeater on 919.something near my sis-in-law's house. I've NEVER heard anyone use it, and even with my sad little scanner, it's close enough if it ever did more than ID.

    I agree, nice post by N0FPE.

    Also, the problem with the paging idea - and it's one I've thought of too - it wouldn't be legal unless only licensed hams had access to any function that would make the transmitter key up. That kind of dilutes the apparent usefulness.

    Ah well, at least everyone it thinking!!!! And that's a GOOD thing.

    Chris
     
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