What is this RF connector?

[G6ONEDave]

Hi, hope someone on the forum can identify this RF connector. There are 2 of them and they are surface mount to the pcb of a mini frequency counter module. Sorry the image has come out blurred, it was in focus until I pressed the button at which point the image became blurred and then the camera took the pic. This is the best out of 4 pics.

Dave

[Herald1360]

Not same module but possibly clearer pic of similar connector here:

https://www.ebay.co.uk/itm/313500102790

[duncanlowe]

Mmm. Are you sure they are connectors? The two things to the left that I'm guessing you mean look a lot more like switches to me. That's from looking at an online listing for something that seems the same. I'd guess the RF connection is to the 2 pin jumper marked S and Gnd)

[McMurdo]

the 2 white connectors look like standard JST XH or similar. The 2 gold & silver things are tact switches

You could always solder wires to the back!

[G6ONEDave]

I must have one of these frequency counters with seized tact switches. I just checked the other one and these gold plated buttons are indeed tact switches. This means that the connector labelled 's' must be the signal input. Very strange choice of connector for a counter that spans 1Mhz to 1.1Ghz. I have purchased some other counters that don't go up as high in frequency and they have gold plated SMB or similar type connectors.

Now all I need to do is find out what the 2 switches are for, given that they will be inaccessible once the display is mounted to the front panel of my adjustable frequency modulator. These will be used to display Band IV/V modulated output frequencies for 625 line, hence the upto 1.1Ghz (to cover 800Mhz frequencies). There is no mention of switch function that I can find, so will have to try pressing them to see what happens, although if the counters display correcly from power up, I'll leave the switches alone.

Thanks for all the comments.

Dave

[HECTOR63]

Dave I have the same module here aswell, the top connector is + and - DC Voltage PSU input and the one to the right is Earth and signal in for frequency. The buttons to the left are to program the stepped IF frequencies required to be able to read the frequency as per input etc. I did have a programming advice sheet on this as intended to use on a Trio R1000 with a faulty driver chip. There is a you tube video I posted about this a while ago on the forum but havent got round to fitting or programming as yet as still puzzling over as to which components and there board IDs were removed to enable its operation. I did mail the video takers for advice but got fluffed off with 'Just a bunch of components and no list was available and keep watching the video'!

[HECTOR63]

https://www.vintage-radio.net/forum/...d.php?t=178068

Give this a try and viewing, if I can find the advice sheet I received with the one I purchased from amazon i will scan and upload, just have to find it!

[G6ONEDave]

Thanks for that Hector63, I'll try powering it up Monday/Tuesday and see what results I get with different input frequencies. I certainly was not expecting there to be programming switches, so will investigate further. Depending on whether it forgets settings after power down will dictate whether I will need to extend wires from the switches to the front panel for resetting the display purposes. Possibly a good idea to do this as the finished UHF modulator will be rack mounted and it will be difficult to access those switches after installation.

The other types of counter modules that I've used only had connectors, there were no switches involved! Maybe I was just lucky with those. I'll report my findings once I've tried this counter on the work bench.

Dave

[HECTOR63]

Many thanks for the update Dave-yes I think once you have it powered up it may be one button selects an internal menu and possible scroll function then the other shifts the frequency points as required to set the IFs etc, or something like that. Likewise I must admit I hadn't got round to powering mine up yet but look forward to and advices on your testing. Lucky I found a replacement driver chip for the R-1000 (bit of a 1off new/old stock on eBay) so if that all works out okay then that will save a lot of fiddling around with what I thought might be a straight forward set up via the You tube guide-but still puzzling over that one, must be getting too old for all this jazz LOL!

[Terry_VK5TM]

Originally Posted by G6ONEDave

Thanks for that Hector63, I'll try powering it up Monday/Tuesday and see what results I get with different input frequencies. I certainly was not expecting there to be programming switches, so will investigate further. Depending on whether it forgets settings after power down ...

Dave

They store the settings in EEprom so they don't lose them when powered down.

[G6ONEDave]

I've now had a play with this frequency counter module and here are my findings to date. Firstly the arrowed switch changes the displayed numbers from 3 decimal places to 4 decimal places. The other unmarked switch is for setting I.F. offset. I don't need that function for my purpose but guess that once in that mode pressing both the switches will give increments up or down accordingly.

I powered the device from a PP3 battery first, which was actually going flat at 7.9v, so I later tried a bench supply at 9v, having said that there was no difference in operation.

I supplied a signal from my Advance E2 sig gen feeding both this frequency counter module and my Blackstar Meteor in parallel. The first test was at 593Khz, which is below the 1Mhz advertised range for the counter module. This was displayed as 5.93Mhz, whilst the Blackstar displayed correctly.

Next I set the E2 to 52.49Mhz and both counters agreed. I then set the E2 to 82Mhz and again they both agreed.

Then I slowly increased the output towards 100Mhz, which is at the top end of the E2 sig gen. This where things went a little strange, as the Blackstar was quite happy showing the E2 set frequency but the module being tested began to display what appeared to be harmonic frequencies. As I increased the E2 output frequency to beyond 90Mhz the frequency counter module reset itself to display 0.000Mhz! All rather odd and for me somewhat dissappointing since this module is meant to be designed to go upto 1.1Ghz.

Something else to watch out for is the signal input wire. If you touch or go near the red insulation whilst there is a display on the counter, the display changes by several Mhz! As I said before it's a strange choice for the input connector to put RF into. I am guessing that this counter needs a strong RF signal to stand any chance of going higher in frequency.

Well it looks like I'll have to rethink about suitable frequency counter modules for my Band IV/V modulator unit. The other counter modules that I've purchased don't behave with any of this fun and games, it's just that they have an upper limit around the top of Band III.

I'll have another go in a little while, this time with a UHF pattern gen to see if this 1Mhz-1.1Ghz counter can display a correct frequency, as compared with my Blackstar meteor.

Hope this is of interest.

Dave

[G6ONEDave]

Further test.

Labgear colour bar gen output showing 419.4Mhz to 419.7Mhz varying on the Blackstar Meteor and 0.0000Mhz on the 1Mhz to 1.1Ghz frequency counter. Tried capacitor coupling to the counter module with nearest disc ceramic to hand (1nf) and got 81.0Mhz to 81.9Mhz display. Did not have the signal earth attached on this test. Last attempt will be to try a coax soldered directly to the counter module with a 100pf cap in series with the input. If that does not solve it then it's either find a different counter module or use some sort of pre-scaler, which defeats the object of the exercise since these modules are supplied as going upto 1.1Ghz.

Dave

[G6ONEDave]

And my last test with the coax soldered direct to the pcb and a 100pf ceramic cap from pcb to coax inner made no difference to how the module behaved. It did however stop the hand capacitance effect on the red wire. It seems that these 1.1Ghz counters don't work reliably above 100Mhz input frequency. So it's back to the drawing board for a total rethink for me!

Dave