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  #1  
Old 03-11-2019, 11:09 PM
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aidynphoenix aidynphoenix is offline
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where to attach VHF/UFH to coax adapter?

hello, i have a elderly RCA EGR293S television, dated 1982
it has terminal style inputs but isn't clear on which ones to use with my 75/300 ohm coax adapter. i simply want to use channel 3 with a VCR.
i tried different positions but could not get a picture or audio.
i could also not find a user manual

any help would be appreciated.





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  #2  
Old 03-12-2019, 06:58 AM
zeno zeno is offline
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Use the pair on bottom right that says VHF between them.
If you still get nothing the tuner is probably out. I cant remember
what tuner this uses but the ones in bigger sets had a lot
of cold joint problems. You can also try running the CH 3 adjustment
through its range.

73 Zeno
LFOD !
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  #3  
Old 03-12-2019, 07:03 AM
zeno zeno is offline
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Another thought. The other bottom pair may have had a jumper on them
so try that also....
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  #4  
Old 03-12-2019, 10:22 AM
dieseljeep dieseljeep is offline
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Quote:
Originally Posted by zeno View Post
Use the pair on bottom right that says VHF between them.
If you still get nothing the tuner is probably out. I cant remember
what tuner this uses but the ones in bigger sets had a lot
of cold joint problems. You can also try running the CH 3 adjustment
through its range.

73 Zeno
LFOD !
I have the same set and you're right about the terminals. Leave the white wires disconnected.
The set uses a varactor tuner with the settings on the side under the cover.
Great picture on those little sets.
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  #5  
Old 03-12-2019, 08:18 PM
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aidynphoenix aidynphoenix is offline
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thanks for the help guys.
i tried messing with it again tonight, i had static in the picture before but not now, the screen is just black.
but now that i have installed a jumper on the bottom left two terminals and the adapter wired up to the vhf connections i am able to get some audio among lots of static while on channel 2. the vcr is set for channel 3. but no picture right now. it seems if i wiggle my adapter around the static comes and goes, it seems to sound best with my hand wrapped around it like a insulator.
i think i am going to order another 75ohm/300ohm adapter to try.
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Old 03-12-2019, 08:55 PM
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aidynphoenix aidynphoenix is offline
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ok so i kept messing with it. i tried a different adapter and got a color picture and stable audio this time after moving the channel 3 adjustment. however it is the other adapter that came with the one i could not get a picture with.. was i using the wrong adapter? this is the adapter i managed to get a picture with.
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  #7  
Old 03-12-2019, 09:28 PM
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Electronic M Electronic M is offline
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Both adapters are valid...The other one probably got the kiss of death from lightning at some point in the past.
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Old 03-13-2019, 03:58 AM
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AlanInSitges AlanInSitges is offline
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Why not just connect to the coax to the 75-ohm input?
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  #9  
Old 03-13-2019, 08:15 AM
zeno zeno is offline
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Quote:
Originally Posted by AlanInSitges View Post
Why not just connect to the coax to the 75-ohm input?
this one dosnt have 75 ohm in. For VHF it is still like an old set. He
is going from 75 ohm - 300 ohm - 75 ohm tuner input with
isolation built in.
The internal antenna input is 75 ohm but not through an F connector.
Thats what the jumper was for.

73 Zeno
LFOD !
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  #10  
Old 03-13-2019, 12:02 PM
vortalexfan vortalexfan is offline
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I have a Zenith TV that's very similar to this TV except my Zenith has a 75 Ohm input already built into the set and it has a digital readout on the front panel that's 125 channel capable (Cable and regular Antenna) but my TV also uses a jumper for the antenna but whats weird is that the TV doesn't have a built in antenna but it has a jumper for one and it has a hole on top of the TV for an antenna to be inserted (using Zenith's proprietary half inch antenna mount hole as opposed to the usual quarter inch antenna mount hole) but there was no antenna with the set when I got it.





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  #11  
Old 03-13-2019, 01:45 PM
WISCOJIM WISCOJIM is offline
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Quote:
Originally Posted by vortalexfan View Post
I have a Zenith TV that's very similar to this TV except my Zenith has a 75 Ohm input already built into the set and it has a digital readout on the front panel that's 125 channel capable (Cable and regular Antenna) but my TV also uses a jumper for the antenna but whats weird is that the TV doesn't have a built in antenna but it has a jumper for one and it has a hole on top of the TV for an antenna to be inserted (using Zenith's proprietary half inch antenna mount hole as opposed to the usual quarter inch antenna mount hole) but there was no antenna with the set when I got it.
Your picture links do nothing.

.
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  #12  
Old 03-13-2019, 02:26 PM
zeno zeno is offline
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Quote:
Originally Posted by vortalexfan View Post
I have a Zenith TV that's very similar to this TV except my Zenith has a 75 Ohm input already built into the set and it has a digital readout on the front panel that's 125 channel capable (Cable and regular Antenna) but my TV also uses a jumper for the antenna but whats weird is that the TV doesn't have a built in antenna but it has a jumper for one and it has a hole on top of the TV for an antenna to be inserted (using Zenith's proprietary half inch antenna mount hole as opposed to the usual quarter inch antenna mount hole) but there was no antenna with the set when I got it.
The Zenith was packed with a UHF bow tie & the dipole ears.
UHF is 300 ohm no matter what. The ears for VHF went on the screws
& there is a 300-75 ohm built in. The coax loop pulls out & is a direct
75 ohm feed to the tuner. Most outdoor antennas used coax so the jumper
eliminates 2 transformers & there losses. In deep fringe areas often
UHF & VHF lines would be run. Downlead would be 300 ohm for UHF
& coax for VHF ( 300 ohm has much less loss at UHF). The set up
gives complete flexability. The big Zenith ears are common & bigger
so as not to break. The common smaller ears I ordered 50 at a time &
that would last about a month. Just kept 2 or 3 Zenith style in stock.

73 Zeno
LFOD !
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  #13  
Old 03-14-2019, 01:38 AM
vortalexfan vortalexfan is offline
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Quote:
Originally Posted by WISCOJIM View Post
Your picture links do nothing.

.
They aren't links they are pictures that were posted using the insert image command on the top of the reply/comment box. If they don't show up in your web browser might I suggest you try Google Chrome or FireFox web broswer as I can see the images just fine on my end using Chrome.
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  #14  
Old 03-14-2019, 08:06 AM
WISCOJIM WISCOJIM is offline
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Quote:
Originally Posted by vortalexfan View Post
They aren't links they are pictures that were posted using the insert image command on the top of the reply/comment box. If they don't show up in your web browser might I suggest you try Google Chrome or FireFox web broswer as I can see the images just fine on my end using Chrome.
They don't show up here in Google Chrome or Internet Explorer.

Google Chrome shows three of these:



IE shows three of these:




.



.
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File Type: jpg 555b.jpg (3.0 KB, 25 views)
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  #15  
Old 03-14-2019, 09:56 AM
dieseljeep dieseljeep is offline
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Quote:
Originally Posted by zeno View Post
this one dosnt have 75 ohm in. For VHF it is still like an old set. He
is going from 75 ohm - 300 ohm - 75 ohm tuner input with
isolation built in.
The internal antenna input is 75 ohm but not through an F connector.
Thats what the jumper was for.

73 Zeno
LFOD !
I going to check into mine to see how it's connected inside. If the network is properly isolated, I'll drill out the terminal board and install an "F" connector.
I'm not too keen on going from 75 ohm to 300 ohm and 300 ohm to 75 ohm.
The set does work fine the way it is.
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