Icom PW-1 questions

Discussion in 'Amateur Radio Amplifiers' started by KI7AAR, Sep 7, 2017.

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  1. KI7AAR

    KI7AAR XML Subscriber QRZ Page

    I'm still setting up the station at the new QTH and I acquired a used PW-1 last weekend. I've been studying everything I can find on the amp but, I still have a couple of questions that an experienced owner might be able to address.

    1. I've read that the PW-1 power supply is sensitive to power outages, especially quick events where the power drops and comes back on a second later. I'm in a rural Washington state and I've seen a few of these events. I'm considering the purchase of a used 120V, 3000VA server grade sine wave UPS and the PW-1 will operate on 120AC for now. Q: Is anyone running their PW-1 on a UPS or taking other measures to protect it from power line events?

    2. I've read about the CI-V buss collision issues and I actually encountered this this twice last year. I was running a IC-7300 barefoot with HRD, a Bandmaster and Bandpasser. One time the bands didn't follow the 7300 and another time they switched during a JT9 contact. I would like to maintain rig control and I saw the K9JM CI-V router. The problem is that is only has three CI-V ports and I'd like at least four ports.
    Q: Is anyone aware of other CI-V routers or solutions?

    3. Last question, thanks for making it this far. The PW-1 has its own set of bandpass filters. I'm not sure if they are in circuit TX only or TX/RX. Q: Would I benefit from retaining bandpass filters between the 756P3 exciter and PW-1? This would be easier since I have two radios (7300 and the 756P3) and want to keep the bandpass filters on the radio that is not currently running through the PW-1. I may just decide to keep the 7300 barefoot.

    Thanks for any pointers that you can offer.

    Dave, KI7AAR
  2. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    Re the AC power: Remember the PW-1 can only run "half power" (500W output) when powered by a 120Vac source. To run "full power," a 240V source is required.
  3. K6BRN

    K6BRN XML Subscriber QRZ Page

    A good sine wave inverter for 220V that can handle full PW-1 power demand is going to be both rare and pricey.

    Most people who worry about damage from intermittent power dropouts wire a relay in series with the load (the PW-1) that is energized by the 220V line through its own N.O. contacts. When the power drops out, the relay opens and stays that way until a reset button, usually a momentary SPST switch, is briefly pressed to supply power to the relay's armature until it latches back on.

    Brian - K6BRN
  4. KI7AAR

    KI7AAR XML Subscriber QRZ Page

    Thanks. Yes, I read that inthe manual. Its still 400w more than than the station had and I can do enough damage with 500w for now. :)
  5. KI7AAR

    KI7AAR XML Subscriber QRZ Page

    Actually, used 220-240V UPSs are a dime a dozen. However, they typically need 8 to 16 new batteries and that will set you back a few dollars. I don't have 240 in the shack and have no intention of pulling 240 into the shack at this time.
  6. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    Unless you have a really big house, "pulling 240V" into the shack is likely less expensive than the batteries for a 3000VA UPS.

    My service panel is 70 feet or so from the shack, and I did the 240V wiring myself using conduit and wires, plus a circuit breaker and an outlet...total cost about $150.
  7. KI7AAR

    KI7AAR XML Subscriber QRZ Page

    The main breaker box is full and the service is maxed out. It will be an expensive upgrade to run 240 into the shack. This is off topic though, whether 240V or 120V the outages and surges still exist and some protection of an expensive amplifier is necessary. I'm not fixated on having 1kW, 500W is good enough for now so 120V is Ok as well. Obviously 240V is a better, it's just not practical at the moment. I guess that I'm breaking new ground around here on using a UPS to protect an amp. I'm ok with that, just checking to see if someone has been there, done that and what the result was.

    Any thoughts on the bandpass filters or CI-V router question?
    Last edited: Sep 8, 2017
  8. K6BRN

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    Ummm. Yeah... So a working 220/240V UPS (you wanted it working, right?) is NOT a dime a dozen since they need batteries to operate. I.e. rare (if working and affordable) or expensive. Cars are always cheaper without the engines, too.

    Regarding BPFs, you do not say how you are using them. Are you using them for SO2R? If so, one bandpass filter (or bank) will go on the amp output (make sure they are rated to run 500+ watts and have sufficient band-band isolation, usually better than 50db if you will be running the PW-1, make sure the connected radio always goes through the amp) and the other is attached to the 100W radio.

    Regarding CI-V.... You need to find a forum more specific to the topic.

    Brian -K6BRN
  9. K6BRN

    K6BRN XML Subscriber QRZ Page

    Clarification... the other BPF is connected to the 100W radio that is NOT going through the amp.

    Or are you just talking about a TVI filter?
  10. KI7AAR

    KI7AAR XML Subscriber QRZ Page

    The question was geared more around receive bandpass filtering through the PW-1. My interest is SO2R but, not at a contest level. Just want to receive on the exciter rig in search of SSB phone DX while running Barefoot digital modes on another rig on a diffent band. I have a variety of Array Solutions 200w (or so) bandpass filters.

    Anyway, after the UPS discussion I really don't feel like going off topic on 500 watt or kilowatt transmit bandpass filters when that wasn't the question. I would enjoy continuing the conversation with you or someone else if experienced with the PW-1 and it's bandpass filters.

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