Vintage wattmeter - Page 1
Forum section: electronics / testgear

author: K4CUZ
author_rank: Newbie
timestamp: May 11, 2025, 12:48:55 am
content: I got this on Ebay, and want to use it with a ham radio. I never owned a wattmeter, just swr meters, and the Byrd type that most use I can't afford. This one was about $30. Take a look at the connectors, they are not pl259. what are they called so I can shop for adapters. All I find online about this model is a schematic, no user manual. thank you

author: tautech
author_rank: Super Contributor
timestamp: May 11, 2025, 01:14:02 am
content: Quote from: K4CUZ on May 11, 2025, 12:48:55 amWelcome to the forum.Look like vanilla ordinary N-type RF connectors.OD measurement ?

author: Stray Electron
author_rank: Super Contributor
timestamp: May 11, 2025, 01:23:10 am
content: That was a kit that was by Heathkit so it shouldn't be hard to find a complete manual for it. But somebody (I don't remember their name) claims to have bought the Rights to all of the old Heathkit manuals so you're going to have to Pay for a copy of one or else find a used one on Fleabay or some place similar.When I say a complete manual, I mean complete. Since their equipment was intended to be sold as kits, Heathkit included a complete parts list including pictures of the parts, a layout, schematics, instructions how to assemble the kit, alignment instructions, operator instructions, etc.Later in life (1974-ish) Heathkit started selling some of their equipment already assembled and under the Heath or Zenith name and it looks yours is one of those. But AFIK all of the pre-built items were identical to the kits. I don't know what the connection was to Schlumberger but they started adding that name to some of their items in the mid 1970s.PS Found it. Take a look at item # 286551000528 of Fleabay.PSS Mods.dk says that they have a manual as well as the schematic for it.

author: WattsThat
author_rank: Frequent Contributor
timestamp: May 11, 2025, 11:28:43 am
content: Heath was owned by Schlumberger in the seventies. When I worked at Heathkit store #42 1973-1976, our paychecks were directly from Schlumberger, not Heath, IIRC.During the period that I worked there, they sold some test equipment models pre assembled with the white and blue color scheme labeled as the OP’s find “Heath/Schlumberger”. The kit version of the same model Heathkit at the time was a light brown.Takeaway? The OP has a professionally assembled version of the same model Heathkit with a fancy paint job.

author: aeug
author_rank: Newbie
timestamp: May 11, 2025, 10:16:10 pm
content: https://www.vintage-radio.info/heathkitIM-4190/SM-4190 is what you are looking for.

author: Stray Electron
author_rank: Super Contributor
timestamp: May 11, 2025, 11:51:31 pm
content: Quote from: aeug on May 11, 2025, 10:16:10 pmummm. No it's not, that it the schematic only. The OP already has that but wants an operator's manual.

author: K4CUZ
author_rank: Newbie
timestamp: May 12, 2025, 03:40:26 am
content: thanks for all the replies, but all i want to know is how to connect a pl259 average coax cable to it. what is the adapter? I will look up the connector mentioned in first reply. thank you

author: K4CUZ
author_rank: Newbie
timestamp: May 12, 2025, 03:51:59 am
content: This is what I need. Yes, thank you for the info on the N connector

author: aeug
author_rank: Newbie
timestamp: May 13, 2025, 12:20:39 pm
content: apologies, misread it as "had the operating manual and couldn't find schematic" when it was actually the opposite