TE Systems....

Discussion in 'VHF/UHF - 50Mhz and Beyond' started by N8SAN, Apr 7, 2019.

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  1. N8SAN

    N8SAN Ham Member QRZ Page

    Hey everyone! I hope you're doing well.
    Well, I got my Comet GP-3 on top of my mast, approx 45'.
    Not that any of you will be surprised, but what a difference!
    I had it at 10' due to timing and couldn't make repeaters 30 miles away, now I had a qso on a repeater at 60 miles.
    There is a repeater just about 10 more miles north that if I could work, I'd be able to talk to my dad with him only on an HT. I've worked that repeater from his qth on one.

    When I worked the 60 mile repeater, he said I had a great signal and 100% readable, but it was a bit scratchy on the rx.

    The TE Systems 1412G has both amp has a pre-amp, but how good is that pre-amp?
    For the record, my rig is an IC-7000.
    Thank you!
    Ryan
     
  2. KA0HCP

    KA0HCP XML Subscriber QRZ Page

    In general the purpose of a receiver pre-amp is to compensate for the minor losses in long coax runs; not to give 'super reception" i.e. gain. A pre-amp amplifies both signal AND noise. If you want gain/directivity, get an antenna like Yagi, Quad, Log-periodic.
     
    N8SAN likes this.
  3. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    The preamp mostly helps receivers that are pretty bad and is a needless frill for ones that are decent to begin with.

    Whether it would help an IC-7100, I have no idea.

    If you decide to use the 1412G with the preamp, be very sure to connect a keying line from the Icom to the amplifier (the amp can be keyed by your rig using two pins on the rear accessory connector) and "hard key" the amplifier, don't rely on RF-activated keying. When using RF-activated keying (no control line), the preamps blow out pretty quickly from hot keying spikes. After that, usually the transmitter amplifier part still works, but the preamp doesn't.

    $1 transistor but a real pain to replace it.
     
    N8SAN likes this.
  4. N8SAN

    N8SAN Ham Member QRZ Page

    So the pre-amp doesn't seem like it would be worth that much in this scenario. I did some more poking around and found that even mast mounted pre-amps are to help with extra long runs (coax) and digging signals below the noise floor such as EME. Wouldn't do too much for me.

    Excellent tip Steve! Thank you! I'll look it all up but is it just a circuit completion? (I know that's not the right terms) But basically one pin from the 7000 to one on the amp and same for the other? There's no resistors or true circuit to build?

    I'd still like an amp anyway.
    I've seen some TE systems and Lunar electronics amps from time to time. But have similar-ish specs. Any pro or con between the two of them?
    Or another suggestion for used amps looking to get 150-200watts... I'm all ears.


    Thanks guys!
    Ryan
     
  5. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    The IC-7000 should provide a TX GND line output to key an external amplifier.

    Oops, I just looked up the IC-7000 (don't have one, never did) and it's very, very limited in this capability. You'd use the HSEND contacts from the 13-pin ACC jack (pin 3 pulls to ground on xmit, and pin 2 is ground) to the amp, but per the Icom manual it states this can only sink a max of 20Vdc at 20 mA. The 20Vdc is okay, as the amp only provides 13.8Vdc at its relay keying connection; however the "20 mA" is very light and if that's the limit, almost any kind of amplifier for VHF or HF will blow that circuit. As such, you'd want an amplifier keying interface between the rig and the amplifier keying line. The Ameritron ARB-704 is very common for this, but there are other approaches of course.

    The amp keying circuit is 13.8Vdc at about 100 mA.

    TE Systems has been around a long time; they're here in L.A. LUNAR made good stuff but has been out of business probably 30-35 years so you won't find anything "new" or even "nearly new" from them. In fact, the founder/owner Louis (was WB6NMT in San Diego) recently passed on and is no longer with us. Mirage still makes VHF and UHF solid state amps, and RM Italy makes some pretty good stuff for VHF.

    I don't have an IC-7000 but their published data indicates it runs 50W output on 2m. If so, I'd think you'd want to "step up" to 200W or more for the change to really be noticed. 50W -> 200W is only 6 dB. The RM Italy LA250 runs about 200W output power (needs a 30A power supply, just for the amp) and is reasonably priced for what it is.
     
  6. N8SAN

    N8SAN Ham Member QRZ Page

    Got it. So I have no choice but to run the interface....or make one. Interface isn't a cash killer so that's probably ok. Thank you for looking into that! I would not have caught that the 20mA wasn't enough to key the amp.

    I was thinking the same thing, 200watts, that will max the GP-3.
    Just from the look of the Lunars, they are certainly old, but I love my old Kenwood Hybrids, so there's not wrong with running those? Not terribly worried about service. If they've lasted this long....
    I've always wondered about those RM Italy amps...glad to know they are a good product.

    150-200$ for a 160watt Lunar, would that be acceptable? I know it's not the full 200 but it's also not 550$ cash outlay. Plus with the interface, I'm at my somewhat proposed personal limit of 250$ total cost. :)

    As far as PS I have a 60amp capable PS. So running whatever I need/want won't be limited to that.
     
  7. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Lunar amps were fine! But after all these years, finding one that works properly and hasn't been damaged by previous years of use may be a challenge.

    In any case, I'd certainly want to "see if working" before exchanging cash for hardware.:)
     
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  8. N8SAN

    N8SAN Ham Member QRZ Page

    Thanks a bunch Steve!
     
  9. N2SLO

    N2SLO XML Subscriber QRZ Page

    Ryan- be careful with your GP3-- max power on FM is probably south of 200 watts.

    The 1412G should be OK- make sure you put a fan on top of it especially for FM to keep it cool. And also make sure you NEVER input more then 20 watts into it-
    or you will smoke it. I have 3 TE system amps, I use the 1452G 350 watt as a back up to my Beko 1KW which I use on SSB, and I have smoked it once by
    transmitting into an open circuit (my bad).. The TE transistors are very expensive, and Dave will do a good job at TE but its costly. Good luck
     
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  10. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Dave at TE can also take 3 months to repair anything. That's the main complaint I've heard about TE.

    Another thing I dislike about their amps (although Mirage and others really aren't any better) is the use of PCB relays which absolutely do wear out and are a PITA to replace. They're not expensive...just a time-consuming task.

    I'd us PINs for this and make them robust enough they'd never need replacement. Cost differential probably less than ten dollars.
     
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