Archer/Radio Shack Time Base Generator - Page 1
Forum section: electronics / repair

author: Old Don
author_rank: Regular Contributor
timestamp: September 03, 2017, 12:38:42 am
content: I picked up an old R.S. Archer Time Base Generator (kit?) and when I opened the metal case up the PCB was stuffed with components, but the circuitry was not wired to the front panel rotary switch, the power LED wasn't connected and ditto with the internal/external source switch. Not a high buck item, but I'd like to play around with it and finish it. There's a bunch of marked holes on the pcb for wires going to these things, but they are not labeled other than "A" - "M" (I think) and so no clue as to which ones go where. Can someone supply me with a copy, or a link to, the assembly instructions/schematics so I can finish it up. Thanks!

author: Old Don
author_rank: Regular Contributor
timestamp: September 03, 2017, 02:08:43 pm
content: Thanks for the link. I'm still not sure of the slider connections to the pcb, but I guess I can work that out by testing for outputs from each divide by ten IC in series.

author: Cyberdragon
author_rank: Super Contributor
timestamp: September 03, 2017, 05:01:18 pm
content: If it's a kit, double check component placement and polarity just to be sure, you never know what the previous builder could have messed up.

author: floobydust
author_rank: Super Contributor
timestamp: September 03, 2017, 05:22:46 pm
content: Archer Project-Board 277-115 Time Base Generator. I found a little bit of info on it.Radio Shack Catalog Archives (html)1978 pg 100 (catalog seems to have wrong part number 276-115, fixed to 277-115 in 1979) Symmetrical Divide by 10 counter/divider, a Line Frequency Counter/Divider (60Hz) or a Binary coded decimal Counter"Seven decade divider IC's (part number? Vcc pin 5, GND pin 10) that can be cascaded.It looks like jumpers can set many possibilities, then fed to the rotary switch.Input is low level probe, 10MHz XTAL osc, or maybe AC line.

author: Old Don
author_rank: Regular Contributor
timestamp: September 12, 2017, 01:40:37 pm
content: Thanks for digging that up. Power supply is not included and requires regulated 5VDC of unknown milliamps until I fire it up the first time. I'll use my GW Intek pwr. supply for testing it since it has a fixed 5 volt output. Once I know everything functions I'll most likely build a small 7805 board up inside the case with a jack on the back panel and power off an external pwr. brick. The fun is in figuring it all out. Then I've got to figure out just what useful purpose it serves so I can put it to use.

author: merseyless
author_rank: Contributor
timestamp: December 05, 2017, 07:21:51 am
content: I have one of these sitting right in front of me that I just finished building today. Bought the magazine/pcb at a hamfest earlier this year. Give me a bit of time and I'll scan the document for you.

author: Old Don
author_rank: Regular Contributor
timestamp: December 06, 2017, 08:32:46 pm
content: Thanks it would be nice to have the step by step so I can check if everything is checked off before powering it up.You "solved" some of my questions just by posting the photo. The schematic somebody posted earlier shows the wiring to the main switch as being shielded and yet there's no ground connections near each signal pickup point. So I was guessing that the shielding wasn't necessary and your wiring shows that it isn't needed. Also, you have a jack on the rear panel for power. My case has no holes in the rear of the case and I wasn't sure if I should drop in an AC to regulated 5VDC power supply or try to find a wall wart and wire it in. Guess I'll drop in a regulator and find a wall wart.

author: merseyless
author_rank: Contributor
timestamp: December 09, 2017, 03:50:18 am
content: Link to manual, it was taking too long to upload to the forum.https://goo.gl/tZtcUz