121.150 000 mhz Referenc how to turn it on. - Page 1
Forum section: electronics / projects

author: Isad
author_rank: Frequent Contributor
timestamp: July 11, 2015, 06:15:21 pm
content: So i got 2 of these guys from some old tv stuff that they had throwen out atthe transmit towers.Now my question is how do i turn these thing on and could i seeanything on a 70mhz rigol oscilloscope.And the last photo is from the Amp idk how many watt it is but its huge.Sry i just edited this here the amp has nothing to do with the referenc.

author: gilbenl
author_rank: Regular Contributor
timestamp: July 11, 2015, 08:19:30 pm
content: Not knowing much about TV equipment, on image 5 you can see a polarity indicator by C30. Start there and buzz out the positive rails on the connector. It appears to have two entirely discrete paths. You can probe output via the coax on the back.

author: Isad
author_rank: Frequent Contributor
timestamp: July 11, 2015, 09:46:44 pm
content: Quote from: gilbenl on July 11, 2015, 08:19:30 pmImage 5 is another thing i just put in here for a teazits not part of the referenc it the amplifire of the unit.I wanted to go probe and put voltages accrose but since i only have 2and dont really want to trash 1 i didnt do it.As i saw its a oven conrtolledoscillator by the looks.

author: LaserSteve
author_rank: Super Contributor
timestamp: July 12, 2015, 03:25:26 am
content: CA2650 is a Motorola or TRW RF amp module. Most modules from the CA series Broadband CATV family , in that package, usually have a center pin that gets +24V. They run from 100 mW to several watts output depending on model. Check the datasheet first. I'd take the amp out of circuit if I was experimenting with power connections. The amps usually do not like accidental reverse bias and in some cases do not like running without a 50 or 75 ohm termination.A typical CA series pinout would beRF in, Ground, Ground, V+ ,Ground, Ground, RF Outor if it needs a bias current, would beRF In, Ground , +Bias, Ground, V+, Ground, RF Out.After some on-line searching, looks like CA2650's data sheet never made it out of the CATV databook or is a house marked part. Sorry...It will always be RF in and RF out on the outermost pins on standard parts..My guess is the bottom most picture is a certainly a RF amp, The Anaren part is a Hybrid 90' Coupler, 1-H0262. Those two white ceramic dots are RF transistors, usually FET or Bipolar, and certainly capable of some substantial RF power.Steve

author: Isad
author_rank: Frequent Contributor
timestamp: July 12, 2015, 07:30:51 am
content: Quote from: LaserSteve on July 12, 2015, 03:25:26 amThanks for the help i really didint know that.But as i said i am not after the instruction to the ampi just wanted to know how to turn the oven controlled oscillator on.

author: codeboy2k
author_rank: Super Contributor
timestamp: July 12, 2015, 12:32:47 pm
content: No one will be able to tell you how to power that reference unless someone has seen that before and used it.Since that's going to be very unlikely, you can start by tracing some of the pins at the back, to determine if they are at least inputs or outputs. You should expect to have a GND, a voltage input, a reference output, and maybe a tuning voltage input. There may be another output (i.e. oven "on" output, or a "ready" output )Once you determine which pins are inputs and outputs, then try to determine the function. i.e. power input, tuning input, etc.I'll tell you right now the GND is the bottom connector (seen on your first picture)

author: Isad
author_rank: Frequent Contributor
timestamp: July 12, 2015, 12:43:06 pm
content: Quote from: codeboy2k on July 12, 2015, 12:32:47 pmWell i have traced the pins and as it seems there is 1 ground and 2 other pins wich are in use the other 2 are no connected anywere.I have applyed 5V then 12v and then 24v but nothing showed on the scope it was drawing power about 215ma to 512ma.And btw do i get anything on a 70mhz scope.