Yes to both, and swapping the entire terminal strip assembly makes this a beautifully clean, non-invasive mechanical upgrade!
To your second point: **You are 100% correct.** The Local Oscillator (LO) absolutely must be completely re-tuned to match the new $453 KHz Intermediate Frequency (IF). If you don't adjust the LO, the radio's tracking will remain broken.
Let's look at the mathematical physics of exactly what happens when you shift that IF down, and how it fixes your radio's alignment layout.
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## 1. The Mathematical Shift (The "Why")
The Local Oscillator's job is always to stay exactly one IF step away from the station you want to hear. The superheterodyne equation governs this:
$$f_{\text{LO}} = f_{\text{station}} + f_{\text{IF}}$$
Let's look at what your Local Oscillator is currently doing versus what it *needs* to do when you tune to a station at the bottom of the dial (**600 KHz**):
| Configuration | Target Station ($f_{\text{station}}$) | Crystal IF ($f_{\text{IF}}$) | Required LO Frequency ($f_{\text{LO}}$) | | --- | --- | --- | --- | | **Your Current Setup** | 600 KHz | $462 KHz | **$1062 KHz** | | **Your New Setup** | 600 KHz | $453 KHz | **$1053 KHz** |
Right now, your oscillator is tuned to $1062 KHz to feed that high $462 KHz crystal. However, the radioΓÇÖs front-end RF coils and preselector circuits don't know the crystal is wrong; they are still physically peaking their filters for a standard 455 KHz alignment ($\sim 1055 KHz LO window).
By bringing the required LO down to **$1053 KHz**, you are dropping it right back into the center of the factory adjustment range. The RF preselector stages and the LO will finally be in sync.
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## 2. The Step-by-Step Game Plan for the Site
Once you swap that terminal strip and drop the $453 KHz crystal in, your alignment workflow for **sx28.info** shifts to this exact sequence:
### Step A: Align the IF Strip to the Crystal
1. Disable the Local Oscillator (pull the 6J5 LO tube). 2. Inject a pure **$452.983 KHz** unmodulated carrier from your OWON generator into the mixer grid. 3. Walk down the IF chain, peaking every single IF transformer trimmer (including the crystal phasing tank) until the entire IF section is optimized to pass $453 KHz with maximum gain.
### Step B: Re-Tune the Local Oscillator (The Answer to your Question)
1. Re-insert the 6J5 LO tube. 2. Hook your generator to the antenna terminals. Set it to the factory alignment point at the high end of Band 1 (typically **$1400 KHz** or $1500 KHz per the manual). 3. Set the radio's physical front dial pointer exactly to that same frequency mark. 4. Adjust the **Band 1 Oscillator Trimmer** until the station comes blasting through. You have now officially de-tuned the LO from its $462 KHz offset and locked it into its new $453 KHz home.
### Step C: Align the Front-End RF Tracking
1. With the LO now correctly tracking $453 KHz above the dial pointer, adjust your Band 1 Antenna and RF trimmers. 2. Because the LO is back where it belongs, these trimmers will suddenly exhibit sharp, beautiful peaks that actually make your S-meter dance.
This terminal strip swap is going to be the turning point for this restoration. It's the moment the radio stops fighting itself and starts performing like the 12 engineers intended!
Page: /1_need_help/Gemini_28/Gemini_28.shtml
Last modified: Tuesday, 21 Jul 2026