Need info on Ameco pre-amp..

[wb1ead]

Hello all..well after succesfully de-thawing from Nearfest..I decided to check out my "goodies" haul..one item really has me stumped..I picked up an Ameco PT Preamplifier..notice I didn't say PT-2 or PT-3..not sure what model# this is??..on the front it just says PT..no number..and sorry no digital camera..runs on 110vac..has a 6EH7 as the RF amp..there's a relay..I assume it bypasses on transmit?..how many watts???
          No this is one unit I know little about as you can tell..I tried searching the web and BAMA..if I can find the source for an op manual and info that would be great..how about it fellas..can someone forward a PDF manual or at least fill me in on the basics..one thing that really puzzled me was to find 4 110vac outlets on the back..I guess I wasn't paying attention to the very few ads in the ol' QSTs I have..don't remember any of that          thanks agn gang!..you've always come thru b/4 and for that I'm most grateful!               73 de DAVE

[Pete, WA2CWA]

First item in my Google search:

[wb1ead]

Yup that's it Pete..any chance on a manual somewhere's?..1st of all I'm not a lazy so and so..I honestly know about as much as to get me here and e-mails..I'm most impressed you got any kind of pic..perhaps Google is where I should be..as Yahoo always fails me seems like..since I've never had the oppertunity to use one of these(PT) it's a bit mysterious to me..tnx for any help in addition you can provide..I realize it's a "trivial" matter again
tnx!!             73 de DAVE

Just a note here: myself and Tom W0TDH have been digging thru the web searching for a downloadable op manual but so far no luk..I hate when that happens..and frustrated that I lack the neccesary expertise to find this..oh well         73

[Mike/W8BAC]

Hi Dave,

I have owned many of the Ameco preamp's made but all of them solid state. I didn't know they made a tube type. That's cool. The earliest model I owned was a nuvistor and the later models use a 222 transistor if I recall correctly. They work very well and spruce up the front end of just about any boat anchor receiver or transceiver.

 The carrier operated relay switches out the preamp on transmit if your using a transceiver but the amp can be used with separate components by placing preamp in the receiver line from the Dowkey T/R relay.

Topically the amp will handle 100 watts so put it in line between the transceiver and linear. One thing that will let the magic blue smoke out is when using a transceiver with the antenna disconnected. Of coarse, that never happened to me  . The 120 volt outlets come in handy but keep the current low.

Give that a try and I think you will be very pleased the first time you turn a weak, unreadable, station into a workable QSO. Good question Dave. Good luck finding the paperwork.

Mike

[wb1ead]

Hey tnx Mike for a little more background on this puzzling mystery..I'm fairly certain how it all works just not 100% sure of power handling capabilities..yah I agree on the tube versus solid state thing..like you I also have seen a few ALL solid state but never until now a tube version..and then again the reason I requested a possible manual/schematic is to verify whether the 6EH7 is THE correct tube here..RCA tube manual shows it's applicable in that use but so are many others..some better some worse..also there are two resistors in circuit at the tube base which look like Ameco shoulda picked 1 watt if not 2 watt types as both are heat discolored and bulging out..tuff to identify the color band for sure..so yes indeedy would love to obtain the op manual or schematic b/4 I even attempt to use/restore..the help/info was what i counted on..someone who at least had a passing knowledge of the pre-amp.....thank you Mike!..I'll keep my fingers crossed someone will come thru with the manual/schematic..73 de DAVE

PS: by the way Mike my plans were to use with the Halli SX140/HT40 combo recently restored as the rcvr is a little lacking on 15 and 10mtrs..exactly as you suggested in the rcvr line..should work

[KM1H]

The 6EH7 is the best of the readily available front end tubes. It has a very low noise figure and will not fold up from strong signals as do nuvistors and SS versions.  Ive used one for years as a general purpose preamp.

Carl
KM1H

[wb1ead]

Hi Carl..hey tnx for ur input on the 6EH7..when I said better or worse I was paying attention to the transconductance ratings..oh for sure the 6EH7 is a very good tube..but is that the REAL honest to gosh tube that goes in that pre-amp?..today I've spent a bunch of time up and down the web..Sams photofacts..sites of free downloadable manuals etc..unless it's right there in front of my eyes no way can I find a "free" source for the manual/schematic..two of the resistors on the tube base look stressed out..dark dis-colored and bulging in the center..I can't make out the color bands..I'd like to replace them but experimentation was never a hi point with me..so ya see Carl what I got here seems like is a "stump the Scwab" thing..at this point I will happily settle for the schematic..I'm guessing this is a PT-1 model but that's about it..Petes pic is right on the money....
               Tom W0TDH has e-mailed the current owner of Ameco so maybbbbeee this will pan out
Tnx to Pete Mike and Carl for ur info..many tnx too to Tom for his time in researching this out..keeping my figers crossed!!
                                                  73 de DAVE

[Pete, WA2CWA]

today I've spent a bunch of time up and down the web..Sams photofacts..sites of free downloadable manuals etc..unless it's right there in front of my eyes no way can I find a "free" source for the manual/schematic..at this point I will happily settle for the schematic..I'm guessing this is a PT-1 model but that's about it..Petes pic is right on the money....
                                                  73 de DAVE

Sometimes you just have to bite the bullet and open the wallet. And, it is Model PT.

[WB6NVH]

This must be the season for those to surface.  I picked up an "Aerotron era"  PT nearly identical to yours from a "free" pile at a nearby hamfest two weeks ago.  The only difference is that the pilot lamp in mine has a smaller red lens.

There should be a paper label on the bottom of the case showing how everything is supposed to hook up.  There is a stern warning that the transceiver power cord must be plugged into the PT and not the wall outlet directly. I don't know why.  Theoretically, I could scan this label for you if it's missing on yours.  The only issue is whether the riveted-on feet will bring the bottom panel out of focus on the scanner.

[wb1ead]

Hello all..well with Petes help I now have a real live schematic..not without it's share of problems for me..I couldn't read the schematic at 1st..just random lines and a number or two..evidently this computor don't do that stuff..Tom W0TDH sent me the schematic pulled from here and forwarded thru Hotmail..NOW I CAN read it..Thank you Pete and Tom and tnx too to WB6NVH who offered to scan the label..no that's ok but thank you anyway..yes like urs mine has a slightly smaller red on lite too..just as well the rig/rigs have to be plugged in on the unit as I'm running outta plug in spots anyway..after I re-attach the grounding wires to the 4 receptacles(all were cut off/removed??) even the main plug the ground was removed??..by the way you can see where the paper label was from the glue residue..interesting!    tnx all the matter is FINI!!
 

                              73 de DAVE