Mini-Kits
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Matthew Lawson
Sep 15, 2016, 12:40:28 PM9/15/16
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Has anyone done business with these guys? They has some really interesting kits and parts with some MW stuff.
Paul Drahn
Sep 15, 2016, 1:45:13 PM9/15/16
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The exchange rate shows $1Au = 0.75 US, so be sure to factor that
plus shipping.
Paul, KD7HB
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Charlie Panek
Sep 19, 2016, 4:44:59 PM9/19/16
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I bought their EME-157 2m mast-mount pre-amp kit (but put it in my own enclosure). Seems to work just fine, although when I put it up I also upgraded the feedline from RG-213 to LMR400, and that seems to have eliminated the need for the preamp. I don't really notice a big change in the S/N ratio with it in or out. :-). the kit went together smoothly for me (It helps that I have access to a good SMT soldering station).
I see that model has been replaced with a new model, the EME-220-2m, which has a lower noise figure, and a higher power rating on the relays. Still $55 AU ($41 US) for a preamp with relay switching good for about 500W when used with sequencing, or 100W with RF sense, is a great deal. Remember that exchange rate works in your favor. Way cheaper than those German preamps! If you blow one up, much less pain in the wallet :-)
Charlie KX7L
Edward R Cole
Sep 19, 2016, 6:04:21 PM9/19/16
to losts...@gmail.com, PNWVHFS
Charlie,
Your comments got me curious to check out the preamp. Link goes to AU supplier but specs on their website show NF=0.8 dB and min gain of 10-dB up to 18-dB. Power handling =100w CW (which would also include FM). 500w PEP (which translates to 250w average power as read by most SWR meters) is for use when relay contacts are not "hot switched" which is what RF sensed preamps do. If you do not use a sequencer to prevent the TR relays from switching high power then its likely you will cause the PGA-103 to fail, after which it will not appear to help weak signals very much (if it passes any signal at all).
I built several PGA-103 VHF preamp boards in spring of 2015 for WA3IAC. Don't have my notes handy, so from memory they worked OK (showed moderate gain guessing 12-15 dB). I have no way to measure NF but guess they are probably 0.8-1.0 dBNF. This is OK to boost sensitivity of older VHF radios having NF in the 10-12 dB range (like the FT-847), but not equal to a mgf-1302 GasFet which is used in ARR preamps (typ. 0.5 dBNF, 22-25 dB gain).
Replacing the mgf-1302 with a NE334S01 improves NF down to 0.3 dBNF range. This is the device in my super-eme preamps from WA2ODO which sell for $75-85 US. I understand that exchange rates and shipping may make the costs much higher in AU. BTW I have substituted the NE334S01 for the mgf-1302 in ARR preamps getting noticeably better performance. It does require adding a resistor to lower gate bias down to 1.5v from the 5v that is std in ARR preamps (LM78L05). Neither the P144VDG or WA2ODO preamps switch transmit power around the preamp so you need TR relays in addition.
0.8 dB NF may help sensitivity if your radio has high NF but its certainly not what I would consider eme performance. Top eme preamps are getting 0.1-0.2 dBNF with a lot more gain. Also if you live in a high noise environment lowering NF may not see much improvement.
Normally, I would expect a good preamp to show a 2 to 3 S-unit rise in noise level when the preamp is turned on when connected to an antenna.
73, Ed - KL7UW
At 12:44 PM 9/19/2016, Charlie Panek wrote:
Your comments got me curious to check out the preamp. Link goes to AU supplier but specs on their website show NF=0.8 dB and min gain of 10-dB up to 18-dB. Power handling =100w CW (which would also include FM). 500w PEP (which translates to 250w average power as read by most SWR meters) is for use when relay contacts are not "hot switched" which is what RF sensed preamps do. If you do not use a sequencer to prevent the TR relays from switching high power then its likely you will cause the PGA-103 to fail, after which it will not appear to help weak signals very much (if it passes any signal at all).
I built several PGA-103 VHF preamp boards in spring of 2015 for WA3IAC. Don't have my notes handy, so from memory they worked OK (showed moderate gain guessing 12-15 dB). I have no way to measure NF but guess they are probably 0.8-1.0 dBNF. This is OK to boost sensitivity of older VHF radios having NF in the 10-12 dB range (like the FT-847), but not equal to a mgf-1302 GasFet which is used in ARR preamps (typ. 0.5 dBNF, 22-25 dB gain).
Replacing the mgf-1302 with a NE334S01 improves NF down to 0.3 dBNF range. This is the device in my super-eme preamps from WA2ODO which sell for $75-85 US. I understand that exchange rates and shipping may make the costs much higher in AU. BTW I have substituted the NE334S01 for the mgf-1302 in ARR preamps getting noticeably better performance. It does require adding a resistor to lower gate bias down to 1.5v from the 5v that is std in ARR preamps (LM78L05). Neither the P144VDG or WA2ODO preamps switch transmit power around the preamp so you need TR relays in addition.
0.8 dB NF may help sensitivity if your radio has high NF but its certainly not what I would consider eme performance. Top eme preamps are getting 0.1-0.2 dBNF with a lot more gain. Also if you live in a high noise environment lowering NF may not see much improvement.
Normally, I would expect a good preamp to show a 2 to 3 S-unit rise in noise level when the preamp is turned on when connected to an antenna.
73, Ed - KL7UW
At 12:44 PM 9/19/2016, Charlie Panek wrote:
I bought their EME-157 2m mast-mount pre-amp kit (but put it in my own enclosure). Â Seems to work just fine, although when I put it up I also upgraded the feedline from RG-213 to LMR400, and that seems to have eliminated the need for the preamp. I don't really notice a big change in the S/N ratio with it in or out. Â :-). Â the kit went together smoothly for me (It helps that I have access to a good SMT soldering station).
I see that model has been replaced with a new model, the EME-220-2m, which has a lower noise figure, and a higher power rating on the relays. Â Still $55 AU ($41 US) for a preamp with relay switching good for about 500W when used with sequencing, or 100W with RF sense, is a great deal. Remember that exchange rate works in your favor. Way cheaper than those German preamps! Â If you blow one up, much less pain in the wallet :-)
Charlie KX7L
On Thursday, September 15, 2016 at 9:40:28 AM UTC-7, Matthew wrote:
- Has anyone done business with these guys? They has some really interesting kits and parts with some MW stuff.
- Matthew Lawson
- KC7EQOÂ
- 442.100 + 100 Hz PL Blyn Mt Repeater
![[]](https://lh3.googleusercontent.com/proxy/ETcB843OZaPCnG3_33JAOS7GQWd0f88ZqsRYiByzmN7EKHk3Nq3NEw-QpW4984m43Ya0zapMDtG5WiwVF8o8cUZrIFokzMzzHXA9LLKpYTPt1hV9nzVKN8OLnAo=w5000-h5000){kind=small}
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73, Ed - KL7UW
http://www.kl7uw.com
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