HAM-MASTER ev-15 receiving booster??

[m3wid]

Hi does anyone remember this bit of kit the "Ham-Master receiving booster EV-15 " 3-30 meg . I will be getting one delivered this week and can't find any info about it at all . Anything regarding this item if you have or owned one would be very useful.
many thanks
Jim.

[K7KBN]

What little I can find about "Ham-Master" indicates that they sell CB amplifiers somewhere in Europe. I'd guess this "receiving booster" is just a broad-band RF receiving amplifier. Most receivers made in the last 20 years or so won't benefit much from something of this general description; it amplifies everything, including noise.

[m3wid]

Thanks for the reply Pat . I operate a shack full of late 70s' kit with reasonable QRP success but have to compromise when it comes to antennas due to space . So I am looking at boosting the input from an antenna with this sort of device. At this time though I am not even sure if this one will work with a receiver only or transceiver. If it gives any signal gain over noise at all I think it would be of use.
many thanks
Jim.

[K7KBN]

It certainly shouldn't hurt anything if the price is right. If it helps, that's a bonus! Good luck; let us know how it turns out.

[m3wid]

HAM-MASTER its true seem to be producing CB amps only today, but in the late 70s' they produced various bits of Amateur gear, not much to be found though on the net. They did an interesting looking 2m home base transceiver. Thats about all the referance to be found out there these days.
As for the EV-15 receiving booster, its arrived and here is the general description of the unit on first inspection.
A simple little metal box w3"xh1.5"xd4" with a little solid state circuit about 30 components in all. The front panel consists of two LEDs "power" and "on air"(TX mode ) an on-off switch integral potentiometer for gain with 0 at the twelve o'clock position. It powers up and gives enough overall gain including noise as expected to lift the s meter from 0 - 9. Signal over noise gain seems to be about 2 s-points. I find its suited to my system as my compromise antenna is usually down the 2 s-points compared to local operators reception of same signals.
I also use extensive audio processing on receive so the noise level is not to much of a problem. Audio on and off the transceiver (FT101ZD III) is constantly monitored on a scope and it is interesting to note that the booster produces a sharper possibly sawtooth waveform giving a slightly thinner sound than the normal sine wave from direct antenna input. Overall I think it is of use and suited to the STN .
Now the bad bit! I am still looking for someone with one of these, as a repair is needed to get this one fully functional.
Here is the fault as far as I can explain it . The relay switches in when you turn the unit on as it should engaging the booster. However when in TX the relay will not stay switched and goes into constant rapid click click click!! Oh dear! I can see a resistor has burnt out and there is also one wire loose . After further inspection the only place the wire can have come loose from is the neg side of the pl259 . The resister is the largest on the circuit 0.5 watt and my deduction is that it is part of the relay circuit that has been fried by to much TX power being applied. Think it was a 10k but cant tell due to carbon burn.

[m3wid]

Sorry about the long winded nature of my post but thats my style I guess. Think I can get it going again,but will wait to see if anyone out there can help before I start experimenting with components out of desperation . The blown resisters remaining code Brown -Black- ??burnt??- gold. Most of the other resisters used in the circuit are 10K .25watt. Thats why I have made my assumption about its value . Yes I know "Assumption being the mother of all ****ups!!" So its a case of HELP for now.