Needle swings backwards, power is too low to calibrate SWR meter and scratchy audio

[Turbo T]

I recently acquired four Royce 1-604 radios for free. At least 3 of them work but all have a few issues I want to address.

The first one transmits good but has a low receive. It sounds as if there was an RF gain knob turned down to maybe 1/2. I've looked inside of the radio for an RX pot but am not seeing one. Does anyone know what pot bumps up the RX?

The second one has good RX but it acts as if it has low power/modulation. It's so low, I cannot even calibrate my Radio Shack 21-534 meter. I know the radio transmits as i could hear myself on the other radio. What do I need to check for?

The third radio rx and tx's but I noticed the audio was scratchy/choppy and distorted. I tried 3 other good working mics and no dice.

The fourth radio goes into transmit mode but the needle swings backwards, and there is no RF output on the SWR meter. I'm wondering if this is a burned final radio...?

Thanks in advance for any help you can provide....would like to revive all these radios.

 

[43Echo695]

One of my rigs had an S-meter that went backwards. It was a variant of the Lafayette Telsat SSB-140.

Also, I think with the RF gain fully open the needle didn't go back to S 0 but settled on about S 5 even with no signals or QRM present.

The backwards meter could be a reversed diode in the meter circuit.

Your Royce may have had a screwdriver expert inside it at some stage.

Either way a visit to the radio doctor will be worth it, especially if the rigs were freebies.

73's

 

[9C1Driver]

I think they were free for a reason, I see some on E-bay for like 6 bucks with no bids. I would mess around with them as a project but they would not be worth the cost of shipping and repair in my opinion.
Maybe cb tricks has some info on them and you could mess with them yourself. Good luck.

 

[STONER 683]

The first rig sounds to me like it just needs a rec alignment. You will have more then one tuning coil for the rec not just one. On an AM rig it wil be at leats 3 or 4 plus 2 more for you signal to noise ratio. See if you can find a service manual for it and go to the alingnment of the rec. It will give you all the coils you need to adjust for rec. Keep in mind that it takes some time to go though a rig so if you got it for free be sure you really want to keep it. Not to mention you really should have the test equipment to do this kind of adjustment.The second one sounds like the final is gone but it still has the driver working.Your still hearing it in another rig because the driver is just putting out enough that you here it that close.Try just replacing the final in that on and it might be ok.Hope this helps..DAVE

 

[STONER 683]

Also I forgot to mention the backwards swing. That always most more times then not is a transmitter misalignment. It's just like an AMP and must be tuned right.If it is out of line this is what you will see.Again the service manual will tell you each step in alingment for the TX.

 

[Lil'Yeshua]

Any comments on a Royce 604?
http://www.cbtricks.com/radios/royce/604/graphics/royce_604_om.pdf
http://www.radiomanual.info/schemi/CB/CB_Radio_tune-up_list_mod.pdf
op:

 

[Lil'Yeshua]

Compressor circuit

The Royce's block diagram shows a compressor circuit

 

[Lil'Yeshua]

Reason I'm asking is I have an opportunity to buy a 604 NOS

 

[Robb]

The AMC/Modulation has probably been turn up too high or the dead key has been turned up - or both.
See if the diode in the mod circuit hasn't been clipped too.

 

[melaza]

First, give it a good alignment / tune-up.

 

[Lil'Yeshua]

Bump **Jump_im** **jump_im** **Jump_im** **jump_im** **Jump_im** **jump_im**
**Jump_im** **jump_im**

 

[Turbo T]

Any comments on a Royce 604?

Yeah...I came to learn they were just a cheap no frills radio, similar to a Uniden Pro 510....I don't think they even had any kind of noise filtering in them. I'll bet they probably were sold new at K-Mart or Zayre.

I still have 2 of the Royce 1-604's in my box of parts radios...my destructive mind is trying to decide how they should meet their demise...

Oh and as far as an NOS make sure you don't pay much for it. Maybe $15 tops.

 

[Lil'Yeshua]

Yeah...I came to learn they were just a cheap no frills radio, similar to a Uniden Pro 510....I don't think they even had any kind of noise filtering in them. I'll bet they probably were sold new at K-Mart or Zayre.

I still have 2 of the Royce 1-604's in my box of parts radios...my destructive mind is trying to decide how they should meet their demise...

Oh and as far as an NOS make sure you don't pay much for it. Maybe $15 tops.

The guy is wanting $55. I posted a link a page or so ago showing that the 1-604 has a compressor in the mic audio feed.
I'm also looking at a GE 3-5813B NOS
Thanks for the info.

 

[Mudfoot]

Radio was for frugal people back in the day.

 

[Lil'Yeshua]

Radio was for frugal people back in the day.

Frugal,yuk!
How about a GE 3-5813B?